BRARY 
 
 IVERSITY Of 
 M.IFORNIA 
 
 :IENCES 
 
 BRARY 
 
KEY 
 
 TO 
 
 A CHART 
 
 OF THE SUCCESSIVE 
 
 GEOLOGICAL FORMATIONS; 
 
 WITH AN ACTUAL SECTION FROM 
 
 THE ATLANTIC TO THE PACIFIC OCEAN. 
 
 ILLUSTRATED BY THE 
 
 CHARACTERISTIC FOSSILS OF EACH FORMATION. 
 
 J AME S HALL, 
 
 PALEONTOLOGIST TO THE GEOLOGICAL SURVEY OF 
 STATE OF NEW YOKK. 
 
 T ' 
 
 KT-y. T 
 
 BOSTON: N*/ 
 GOULD AND LIN COL NT* 
 
 59 WASHINGTON STREET. 
 
 1852. 
 
.* 
 
 Entered according to Act of Congress, in the year 1851, by 
 
 GOULD AND LINCOLN, 
 in the Clerk's Office of the District Court of the District of Massachusetts. 
 
 STEREOTrPED AT THB 
 T^V STEP.EOTVPE FOUNDRY. 
 
f 
 
 Wom^^f 
 P REP ACE. 
 
 THE preparation of the Chart of the Geo- 
 logical Formations was undertaken at the 
 request of S. S. Randall, deputy superintend- 
 ent of the Common Schools of New York 
 and editor of the Common School Journal, 
 and of A. G. Johnson, deputy secretary of 
 the State of New York. 
 
 The object had in view was the introduc- 
 tion of the study of Geology into the schools 
 with better means of instruction and illustra- 
 tion than then existed within the reach o 
 the pupils. 
 
 The work was commenced in September, 
 
 050 
 
PREFACE. 
 
 1849, and completed in December following. 
 Circumstances, which it is not now neces- 
 sary to enumerate, have delayed its appear- 
 ance much longer than could have been de- 
 sired. 
 
 It is now issued, with the following pages 
 of explanatory matter, in the hope that it 
 may render a study so delightful in itself 
 and so practically useful, more extensively 
 introduced and more easily understood. 
 
 ALBANY, N. Y., December, 1851. 
 
INTRODUCTION. 
 
 THE crust of the earth is found to consist of 
 materials which are either in a loose condition, as 
 soil, clay, sand, gravel, etc. ; or consolidated in the 
 form of what are commonly called rocks, as lime- 
 stone, slate, granite, etc. All these, however, are 
 termed rocks by the geologist. 
 
 These rocks are arranged in successive beds or 
 layers, one above another, and are more or less dis- 
 tinctly marked by their mineral character, or by 
 the fossils they contain. Most of these layers or 
 strata were originally formed in a horizontal posi- 
 tion, but have been subsequently deranged and dis- 
 placed, so as to be tilted up, and stand in more or less 
 inclined positions, or even sometimes to be entirely 
 overturned. It is owing to this circumstance, that 
 we are able to explore the strata to a very great 
 depth, and without the necessity of excavating; 
 
6 INTRODUCTION. 
 
 since those beds which are really the lowest, are 
 often broken up, and have their edges raised to the 
 surface, or even to great heights beyond other layers 
 which are above them in the geological succession. 
 
 It is within the province of geology to determine 
 the true position of each layer, and its relations to 
 those above and below it, however confused or 
 obscured may be their present condition; and to 
 present the evidence on which this determination is 
 sustained. 
 
 The chart, to which this book is an accompani- 
 ment, is designed to exhibit to the eye the order 
 in which the successive layers or strata of rocks are 
 arranged, as it has thus far been determined by 
 geologists ; and, also, the characteristic fossils which 
 have mainly afforded the key to this arrangement. 
 It is intended to exhibit the appearance that would 
 be presented if a section, or cut, were made from 
 the surface towards the centre of the earth, thus 
 exposing the different layers to view by their edges. 
 It is, in fact, such a representation as may be 
 seen in the banks of many rivers, as the Niagara, 
 or in the high, rocky cliffs of the lake or ocean 
 shores, only it is much more extended than any 
 such natural exposures. 
 
GENERAL DESCRIPTION OF THE CHART. 
 
 GENERAL DESCRIPTION OF THE CHART. 
 
 Towards the left hand side of the chart there is 
 represented a large mass of rock colored red, which 
 is regarded as the basis upon which, or against 
 which, all the other rocks rest. To the right of 
 this are represented the several successive strata or 
 layers composing the entire series of stratified rocks. 
 By observing the direction of the stripes which 
 represent these strata, and which are in truth as we 
 find them in nature, it will be seen, that by passing 
 along the upper margin, from rigid to left, we pass 
 over the strata in the same order as they occur in 
 passing downwards along the right hand margin of 
 the section. In other words, we may obtain the same 
 information by travelling along the surface of the 
 earth as we should do by penetrating downwards 
 towards the centre. 
 
 In no limited region of country will all the strata 
 here represented be seen ; nevertheless, all these 
 strata, and all the phenomena exhibited, from the 
 granite peak on the left, as far to the right as the 
 limits of the Carboniferous formation, may be seen 
 in travelling over the country from the northern 
 part of New York to the centre of Pennsylvania. 
 In this way, we pass in succession over the out- 
 cropping edges of the different layers which lie one 
 
8 GENERAL DESCRIPTION OF THE CHART. 
 
 above another, in the same order and with the same 
 regularity as are there represented. Many other 
 portions of country would furnish similar examples 
 of this order of succession, more or less complete. 
 
 Since the higher strata are mainly formed out of 
 the ruins of those below their, it is more satisfac- 
 tory to begin our investigations with the lowest beds. 
 
 Let us begin, therefore, on the left of this series, 
 next to the granite, and proceed along the surface 
 (or upper margin of the section) to the right. 
 
 Lying next to the mass marked granite, is a 
 broad purple or grayish colored stripe marked 
 Gneiss and Mica Slate, with beds of crystalline lime- 
 stone; and, in another part of the same, Quartz 
 rocks, Sandstones, Conglomerates, etc. ; which names 
 are sufficiently indicative of the character of the 
 rocks occupying this place in the series. 
 
 Above this, the entire series of rocks is arranged 
 under three grand divisions. 
 
 I. PALAEOZOIC ROCKS. II. SECONDARY ROCKS. 
 III. TERTIARY and MODERN ROCKS. 
 
 I. THE PALAEOZOIC ROCKS (from 7ra>.cao, ancient, 
 and ^wvj, life) are so called from containing the 
 oldest or most ancient forms of plants and ani- 
 mals in a fossil state. These are subdivided into, 
 
 1. SILURIAN SYSTEM, 2. DEVONIAN SYSTEM, 
 3. CARBONIFEROUS SYSTEM. 
 
 The Silurian System is again divided into upper 
 and lower, by a well-marked line of separation. 
 
GENERAL DESCRIPTION OF THE CHART. 9 
 
 Adjacent to the granite, we have represented a 
 portion of this system, in which the strata have 
 undergone certain changes, and have assumed a pe- 
 culiar condition, termed METAM ORPHIC. Rocks 
 of this character are not peculiar .to the Silurian 
 period ; but rocks of any age or of any system 
 may undergo similar changes, by the agency of 
 intense heat ; as the contact or proximity of highly 
 heated vapors, or melted masses of rock. 
 
 II. THE SECONDARY ROCKS are so called from 
 being in a somewhat different condition from those 
 below them, but mainly from containing an assem- 
 blage of fossils of different types from those of the 
 preceding formations, indicating a second period in 
 the age of the rocks. This division comprises, 
 
 1, the NEW RED SANDSTONE SYSTEM, which 
 
 is again subdivided into the PERMIAN SYSTEM 
 and the TRIAS sic SYSTEM; above which are, 
 
 2, the OOLITIC SYSTEM, and 3, the CRETA- 
 CEOUS SYSTEM. 
 
 III. THE TERTIARY and MODERN ROCKS com- 
 prise the third great division of rocky strata, 
 marked by fossils which differ essentially from 
 those of the preceding formations, approaching 
 more nearly to existing forms. In this division are 
 included, 1, the TERTIARY SYSTEM proper, and, 
 2, the QUATERNARY, or deposits of recent pro- 
 duction. 
 
 On the upper part of the map are arranged a 
 
10 GENERAL DESCRIPTION OF THE CHART. 
 
 series of figures of fossils from the systems of 
 rocks just enumerated. These fossils are enclosed 
 in compartments, separated by vertical lines, and 
 within each one of these are represented those 
 fossils which are most important, and characteristic 
 of the system to which they belong. They are, 
 moreover, so arranged, as to be nearly over the 
 upper or outcropping edges of the different systems 
 which they represent. 
 
 In order fully to comprehend the subject illus- 
 trated upon this chart, it will be necessary to re- 
 turn to the starting-point, viz., the granite nucleus, 
 and to pass again from left to right, noticing more 
 particularly the several subordinate formations of 
 which the systems are composed. 
 
 The gneiss , mica slat c , crystalline lime- 
 stone, and other rocks included in the first divis- 
 ion, above the granite proper, are not to be regarded 
 as belonging to the Silurian System. They consti- 
 tute a series of more or less crystalline rocks, in 
 which, thus far, no fossils have been discovered ; 
 and they are more intimately related to the granitic 
 rocks below, than to the formations above them. 
 From their stratified condition, they are regard.ed 
 as having been originally deposited in water, and 
 subsequently, by the action of heat, to have become 
 remarkably altered, and crystalline in structure.* 
 
 * This assemblage of strata is known as the Azoic SYSTEM. 
 
GENERAL DESCRIPTION OF THE CHART. 11 
 
 The rocks of this period are interesting and im- 
 portant from containing the extensive beds of spec- 
 ular and magnetic oxide of iron, in different parts 
 of the United States. 
 
 The series of quartz rocks, sandstones, conglom- 
 erates, and other rocks overlying these, and repre- 
 sented in the upper part of the same division, are 
 also highly metamorphic, and contain, in some 
 places, veins of copper ore, as indicated upon the 
 chart. 
 
 With the blue stripe above the rocks just noticed, 
 commences the SILURIAN SYSTEM, the lowest 
 rock of which, yet known, is the Potsdam sand- 
 stone and its associated conglomerate. It is in 
 this rock, also, that we find the first organic remains. 
 
 It will be observed, that at the extreme left hand, 
 several of the lower divisions of this blue stripe are 
 represented in a folded and contorted condition, 
 unlike the same formations farther to the right, 
 which are but slightly undulating. These are 
 termed " METAMORPHIC ROCKS " of " Silurian age" 
 They are more or less crystalline, and their general 
 features are quite unlike the same rocks where they 
 are unchanged. In tracing them to the right, they 
 gradually lose this character, and assume that of 
 unaltered, stratified rocks, such as sandstone, lime- 
 stone, shale, etc. 
 
 Since ?<K-], examples? are of frequent occurrence 
 
12 GENERAL DESCRIPTION OF THE CHART. 
 
 in nature, and in rocks of various systems, the con- 
 nection of the two has been shown ; and we have, 
 for example, at the beginning of this formation, 
 colored blue, the terms Gneissoid and Granular 
 Quartz rocks, which are metamorphic states of the 
 Potsdam sandstone." In other words, the Pots- 
 dam sandstone, when altered by igneous action, 
 becomes first a granular, more or less crystalline 
 quartz rock, and finally passes into gneiss. 
 
 Next above this we find " Crystalline Limestone ; " 
 and again, in a continuation of the same beds, 
 " Crystalline limestone, Variegated and White Mar- 
 ble" which are metamorphic conditions of the fol- 
 lowing limestones, viz., Trenton, Black River, Birds- 
 eye, and Chazy limestones, and Calcifcrous sandstone. 
 The various limestones named, become crystalline, 
 from the action of the igneous rocks on the left and 
 below them, and furnish the white and variegated 
 marbles. 
 
 In the same manner, the succeeding Chloritic, 
 Talcose, and Mica Slates are metamorphic conditions 
 of the Hudson-river group ; which is itself suscep- 
 tible of separation into several subordinate groups 
 of shales, shaly sandstones, etc., as indicated in 
 another part of the division. 
 
 From this point, or from the commencement of 
 the Oneida conglomerate, the names first written in 
 the subdivisions of the formations, and enclosed 
 
GENERAL DESCRIPTION OF THE CHART. 13 
 
 between parallel lines, are those by which the rocks 
 are known in their unaltered condition. Returning 
 to the upper margin of the section, and reading 
 downwards, the names following those of the rocks 
 are the names of localities or places where the 
 same rock may be examined to advantage, either 
 in ravines, cliffs, or river banks. A few only 
 of the more important localities are indicated, be- 
 ginning with those in America, and followed by 
 those of foreign countries, where the same rock is 
 known to have been discovered. 
 
 It will be seen, that in some instances, the names 
 of two or more rocks are included in the same sub- 
 division, or between the same parallel lines. In 
 these instances, the rocks are closely allied to each 
 other in character, and are not sufficiently distinct 
 to require subdivision by lines. The names are 
 arranged in the order in which the rocks occur in 
 nature. As an example, we have the Calciferous 
 Sandstone, the Chazy, Birds-eye, Black River, and 
 Trenton Limestones, in one subdivision. In these 
 groupings, the name of the locality is placed as 
 nearly as possible to succeed the name of the rock. 
 
 The names of these rocks will also be found 
 repeated near the right hand margin of the chart, 
 and, in the same order, from below upward, as 
 they occur from left to right on the upper margin of 
 the section. In this column will also be found the 
 2 
 
14 , GENERAL DESCRIPTION OF THE CHART. 
 
 names of still more minute subdivisions, into which 
 some of the rocks or groups have been separated 
 in the geological surveys of New York. 
 
 For example, the Hudson-river group consists of 
 three distinct members : the Utica Slate, the Frank- 
 fort Slate, and the Pulaski shales and Sandstones. 
 The division marked on the upper margin of the 
 chart as Lower Helderberg limestones is shown, on 
 the right hand margin, to be composed of the Ten- 
 taculitc or Water limestone, the Pentamcrus limestone, 
 Ddthyris slialy limestone, and Upper Pentamcrus 
 limestone, divisions which are easily recognized in 
 some places, but are very obscure in others. 
 
 The same may be said of the Upper Helderberg 
 limestones, which are capable of subdivision into 
 three distinct masses. The subdivisions into which 
 the Hamilton group can be readily divided, are 
 shown a little within the right hand margin, and to 
 the left of the name of the group itself. 
 
 In several instances, the names by which groups, 
 or rocks of the same age, are known in England 
 are given in parentheses, at the lower end of the 
 stripe, as the Wenlock Formation, corresponding in 
 part with the Niagara group; Caradoc sandstone, 
 with the Hudson-river group. 
 
 In this manner, the strata are all marked as far 
 as, and including, the Coal formation. Above and 
 beyond this, it will be found that the names of 
 
GENERAL DESCRIPTION OF THE CHART. 15 
 
 localities do not, in every instance, immediately fol- 
 low the name of the rock. This difference indi- 
 cates that the rocks have not as yet been distinctly 
 recognized in this country, and, therefore, no 
 American locality is inserted. 
 
 From the Coal period upward to the Tertia- 
 ry, the formations are preeminently European ; 
 they are extensively and very perfectly developed 
 in England and upon the continent, and form a 
 great and prominent geological feature. 
 
 Of the Tertiary System, the two lower members, 
 Eocene and Miocene, are fully recognized in many 
 localities ; while those strata usually denominated 
 Pliocene have not yet been so distinctly recognized, 
 and therefore no American localities are given. 
 
 In the Modern or Quaternary system of deposits, 
 no localities have been given, for want of space. 
 
 From the commencement of the Secondary Rocks, 
 therefore, the English names of the rocks are first 
 introduced, and next to them those of Continental 
 Evirope : first, the German name, in German let- 
 ters ; and next the French name, in scrip type ; 
 and beyond these are given, in Italic capitals, first 
 the names of the continental localities, and finally 
 the English ones, the English name of the rock being 
 again repeated at the right hand margin of the sec- 
 tion. As an example, under the NEW RED SAND- 
 STONE SYSTEM, take the Magncsian limestone, the 
 
16 GENERAL DESCRIPTION OF THE CHART. 
 
 second rock above the Coal measures. This rock 
 has no positive representative in America. Its Ger- 
 man name is Zechstdn and Kupfer Schiefer, (the latter 
 a layer of copper-bearing slate ;) and the French 
 name following it, Calcaire magnesien, is simply a 
 translation of the English. Among the prominent 
 localities are Mansfeld, in Germany, and East Thick- 
 ley, in England, as given on the chart. 
 
 In the OOLITIC SYSTEM, the Lias has been recog- 
 nized in this country, from certain fossils found 
 in the coal beds of Richmond, Virginia ; and above 
 this, none of the members of this system have 
 been recognized in the United States, and conse- 
 quently no names of American localities are found 
 after the names of the rocks. 
 
 It will be seen that each of these systems is made 
 up of several subordinate groups of individual rocks. 
 It will be observed, moreover, that rocks of the same 
 denomination are repeated in almost every one of 
 them. Thus shale, sandstone, and limestone occur in 
 all the systems of the Palaeozoic Rocks. In their 
 general aspect and character, these rocks, in the dif- 
 ferent systems, are much alike ; and it is often only 
 by their contained fossils that we are able to distin- 
 guish them. This repetition of deposits of similar 
 character arises from a continuation or a repetition, 
 at different and successive periods, of causes similar 
 to those giving rise to the first deposits. 
 
GENERAL DESCRIPTION OF THE CHART. 17 
 
 Since all these strata, with the exception of the 
 limestones, were deposited from the mud, sand, and 
 silt carried into an ancient ocean, there must be 
 an entire absence of a formation where dry land 
 existed at the time ; and it will very naturally be 
 presumed that it cannot have the same thickness in 
 all parts of its extent. This is not only true, but 
 many of the formations thin out entirely, leaving the 
 one above and the next below to come in contact. 
 As examples of this, which are represented on the 
 chart, we have the Oneida conglomerate, a rock made 
 up of sand and pebbles, which, in its greatest devel- 
 opment, has a thickness of several hundred feet. In 
 the same manner, the lower Helderberg limestones are 
 represented as thinning out entirely, a feature which 
 is remarkable in those rocks. The Oriskany sand- 
 stone and Cauda-galli grit also thin out entirely. 
 The same feature is represented in some of the 
 rocks of the secondary period, and, as before said, 
 it may occur in any of them. 
 
 This thinning out may arise from the fact that in 
 the wide and deep ocean certain deposits never 
 reached the deeper portions, but subsided along 
 its shores. Or it may have been caused by cer- 
 tain portions being too shallow, or even upraised 
 above the level of the water. It may also have oc- 
 curred in another way. After the deposition of the 
 stratum, it may have been uplifted so near to the 
 2* 
 
18 GENERAL DESCRIPTION OF THE CHART. 
 
 surface of the sea as to have been worn away by the 
 waves, and thus have allowed a succeeding deposit 
 to come directly upon one of preceding date. Such 
 operations have sometimes taken place to a consid- 
 erable extent. We have an example of this erosive 
 action at the termination of the Carboniferous for- 
 mation, where the upper undulating surfaces of the 
 strata of the Coal period have been worn down, and 
 in some places present considerable depressions, 
 from which the strata have been removed. The 
 evidence of similar erosive action is visible at the 
 termination of the Cretaceous system, and before 
 the Tertiary strata were deposited. The same 
 causes have doubtless operated, in many instances, 
 where no evidence is now preserved in the remain- 
 ing portions of the formation. 
 
 The QUATERNARY or MODERN SYSTEM of deposits 
 is represented on the section as covering only a 
 small portion of the surface. This has been done 
 to avoid confusion ; though we know that, in nature, 
 the materials of this age cover almost the entire 
 surface. They have been deposited after the older 
 formations, and since the uplifting and breaking up 
 of the lower rocks, and consequently lie in a hori- 
 zontal, or nearly horizontal, position upon the edges 
 of these rocks, when upturned, or upon their plane 
 surfaces when they have not been thus uplifted. 
 
 The same is also true of the Tertiary deposits 
 
GENERAL DESCRIPTION OF THE CHART. 19 
 
 which have often been made upon the upturned 
 edges of the Palaeozoic rocks, and are thus shown, 
 in a single example, lying upon the edges of the 
 Carboniferous strata. 
 
 We will now direct our attention to the stratified 
 deposits on the left of the granite peak. 
 
 The rocks of Secondary age, the New Red sand- 
 stone, Oolitic and Cretaceous formations, are there 
 represented as resting on gneissoid or granitic rocks. 
 The strata are shown as more or less undulating, 
 and becoming contorted in their proximity to the 
 igneous rocks below, and even entirely metamorphic 
 in their character. 
 
 Strata of this age, both in their normal condition 
 and in various stages of metamorphism, are the pre- 
 vailing rocks of the Alps, the Jura, and the Apen- 
 nines ; and towards the south they are overlaid by 
 Tertiary strata, through which rise the ancient vol- 
 canic vents and active volcanoes of Southern Eu- 
 rope, while the lavas have flowed over the surface. 
 It is intended, in this sketch, to combine the ex- 
 hibition of phenomena which are in reality connected 
 in nature, though spread over a wide surface. 
 
 Besides the formations we have been considering, 
 another series of bands may be seen rising in nearly 
 a vertical direction, traversing or cutting through the 
 strata previously described. These rocks penetrate 
 from below upward, sometimes reaching to the 
 
20 GENERAL DESCRIPTION OF THE CHART. 
 
 surface, and in other cases terminating in the older 
 formations. 
 
 The two on the extreme left are intended to rep- 
 resent volcanic chimneys passing from the sources of 
 volcanic fires to the surface. 
 
 A column of lava is represented as rising through 
 a fissure in the granitic and secondary rocks, dividing 
 above, and extending to two distinct cones, where the 
 volcanic fires have ceased to be active. 
 
 To the right of this column is represented another, 
 originating from a vast reservoir below, and which 
 rises to the surface through two distinct cones, ex- 
 hibiting the character and phenomena of active vol- 
 canoes. 
 
 The others represent Trap dikes, Greenstone 
 dikes, Porphyry dikes, Granite veins, &c. 
 
 From -their character and condition, they have 
 evidently been forced up from beneath, in a state of 
 fluidity, penetrating the superincumbent rocks through 
 fissures and between strata. Among the attendant 
 phenomena of the intrusion of these dikes and 
 Granite veins is the production of faults ; that is 
 to say, fractures and dislocations of the strata, 
 which often extend through a very great thickness, 
 or even for an entire system of strata. The illus- 
 tration of these phenomena is made by a black line 
 following the dislocation of the beds, on each side 
 of which the strata are displaced, so as no longer 
 to be continuous. 
 
GENERAL DESCRIPTION OF THE CHART. 21 
 
 The occurrence of metallic veins in various rocks 
 is represented by lines of color, as well as by name. 
 The production of these rocks is regarded as due 
 to the same causes which produce and sustain vol- 
 canic action at the present time. The fluid lava 
 penetrates the adjoining rocky beds through fissures, 
 and, on cooling, becomes dikes, analogous to those 
 penetrating the more ancient rocks. Portions of 
 the fluid matter also flow over the surface, and 
 accumulate in immense masses, even covering large 
 tracts of country. The same feature is attendant 
 on the Trap dikes, and, in many instances, exten- 
 sive areas are covered by rock precisely similar in 
 character to that forming the dikes, but assuming a 
 columnar form, as represented on the upper margin 
 of the large section, above the New Red sandstone 
 system, and the other above the Cretaceous system. 
 Rocks of this kind, and having this position, are 
 termed basalt, or basaltic rocks. 
 
 Although there is a variety of character and 
 composition in the nature of these ancient dikes, it 
 is not so great as the variety among the products of 
 modern volcanoes. 
 
 In the section which has just been described, all 
 the important geological formations known to exist 
 are brought together and presented in their true 
 order of succession. It is true, that no single lo- 
 cality or moderate extent of country will furnish all 
 the rocks here exhibited. 
 
f 
 22 GENERAL DESCRIPTION OF THE CHART. 
 
 The low section at the base of the chart is one 
 exhibiting the successive rocks and formations 
 which appear along a line, from the Atlantic to the 
 Pacific Ocean, and will afford a good idea of the 
 condition in which rocks are found, with all their 
 disturbances and deficiencies, when examined over 
 a large extent of country. 
 
 Beginning at the eastern extremity, in Nova 
 Scotia, we have a well-defined Coal Formation of 
 the age of that represented upon the larger section 
 above. As we go westward, we find rocks of the 
 Devonian and Silurian periods coming out from 
 beneath those of the Carboniferous period, precisely 
 as is represented in the larger section. In pursuing 
 this direction, however, we soon find the rocks 
 folded and contorted, and becoming crystalline in 
 their character, like the metamorphic rocks repre- 
 sented to the right of the granite, in the section 
 above. In travelling entirely across the White 
 Mountains and the Green Mountains, we find no 
 rocks older than those of Silurian and Devonian 
 age, with occasional intrusions of granite veins and 
 Trap and Greenstone dikes. The section is upon 
 too small a scale to allow of the minute represen- 
 tation of all these phenomena. In the valley of 
 Lake Champlain, between the Green Mountains of 
 Vermont and the Adirondack Mountains of New 
 York, the Silurian rocks are less folded, and grad- 
 
GENERAL DESCRIPTION OF THE CHART. 23 
 
 ually lose their metamorphic character, revealing 
 again their fossils in great numbers.* 
 
 Between the Champlain valley and the central 
 portion of the Adirondack Mountains, the Gneiss, 
 Mica Slate, and Crystalline limestones (of the age 
 of those next the Granite in the large section) 
 come in, in great force, containing extensive beds of 
 iron ore. In the centre of this chain are immense 
 masses of peculiar granitic rocks, forming high 
 mountain peaks. Again, to the west and south-west 
 are the Gneiss rocks, and, above them, the Silurian 
 strata, in a disturbed and partially metamorphic con- 
 dition. From this point, the Silurian strata dip 
 regularly to the south-west, and we pass over their 
 outcropping edges, and those of Devonian and Car- 
 boniferous systems. In this direction, however, we 
 find no higher formations succeeding the coal field 
 of Pennsylvania, and, after passing for a long dis- 
 tance over its various members, as exposed in the 
 valleys and watercourses, we descend again to the 
 westward, passing over the outcropping edges of 
 the various members of the Carboniferous, Devo- 
 nian, and Silurian systems, as far as the rocks of 
 the Hudson-river group. On the west side of the 
 coal field, therefore, the successive formations are 
 
 * It may be remarked here, that even as far east as the Con- 
 necticut River some of the strata still preserve their fossils. 
 
24 GENERAL DESCRIPTION OF THE CHART. 
 
 precisely in the same order, from left to right, as 
 upon the section above. The student will under- 
 stand, that the rocks represented as coming out 
 from beneath the coal formation, on either side, 
 are also continuous beneath that formation, and 
 constitute a part of the great system which so 
 largely pervades the country. 
 
 From this section, it can be readily understood 
 how the coal field of Pennsylvania has once been 
 Continuous with that of Illinois, farther to the west ; 
 and that they have been separated by that agency 
 which has upheaved the lower rocks between, and 
 caused them to dip in opposite directions. When 
 these rocks were uplifted, their edges became 
 broken, and, in this condition, were exposed to the 
 action of water, which has covered the surface ; 
 and by this and other agencies, these projecting 
 rocks have been worn down, and the two coal fields 
 so widely separated. On the western side of this 
 elevation, marked by Cincinnati, we find a repeti- 
 tion of similar rocks, dipping again beneath the 
 Illinois coal field, and, in part, reappearing on the 
 western side, along the Mississippi River. 
 
 Beyond this point are again carboniferous rocks 
 and coal fields, the character and extent of which 
 are riot fully known. 
 
 In this western direction, we find rocks of the 
 Cretaceous system resting directly upon the Car- 
 
GENERAL DESCRIPTION OF THE CHART. 25 
 
 boniferous rocks. By a reference to the large sec- 
 tion above, it will be seen that this implies the 
 absence of the New Red Sandstone and Oolitic 
 systems, which, as before remarked, are usually 
 absent in American localities. Between the mouth 
 of the Kansas River and the summit of the Rocky 
 Mountains, there is a wide extent of rocks belong- 
 ing to the Cretaceous system, and from beneath 
 which appear metamorphic and highly crystalline 
 strata. To the westward, upon these metamorphic 
 rocks, at intervals, rest formations of Tertiary, and 
 even, perhaps, of Cretaceous age. The fossil plants 
 and shells, however, that have been collected, are all 
 of the Tertiary period. 
 
 At all points along this line of section, west of 
 the Cretaceous formation, where the names of rocks 
 are given, it is from specimens that have been col- 
 lected by Captain Fremont and others. At intervals, 
 Basalt and Trap, with more recent volcanic rocks, 
 are known to occur, and active volcanoes exist on 
 the western slope. The metamorphic rocks under- 
 lying all this region are probably all of Palaeozoic 
 age ; and those towards the western margin belong 
 to the Silurian system. 
 
 One of the most striking features presented in 
 this section across the country, is, the great differ- 
 ence in elevation between the eastern and western 
 portions of the continent. This difference would 
 3 
 
26 CLASSIFICATION AND ORIGIN 
 
 be the more striking, were the line carried west, 
 over the higher mountains, as it is at the east ; but 
 it follows a line of travel much below the mountain 
 peaks, which are sometimes represented in the back- 
 ground. This is a very interesting and very impor- 
 tant feature in our continent. 
 
 CLASSIFICATION AND ORIGIN OF ROCK FORMATIONS. 
 
 Rocks are classified and arranged in systems and 
 groups, according to their mineral characters and 
 their fossil remains ; and these are intimately asso- 
 ciated with considerations regarding their origin and 
 deposition. 
 
 One of the most obvious distinctions which first 
 occur is the subdivision of rocks into stratified and 
 unstratified. These terms, moreover, indicate the 
 origin or mode of production of these different for- 
 mations ; for the unstratified rocks are those which 
 have originated from igneous action, or whose earli- 
 est condition has been that of fluidity from heat. 
 These rocks, moreover, are always crystalline in 
 structure ; though this character alone is not suffi- 
 cient to distinguish them from each other, or from 
 stratified rocks which have been subjected to heat. 
 
 'The stratified rocks, on the other hand, have had 
 
OF ROCK FORMATIONS. 27 
 
 their origin from water, and are called sedimentary 
 rocks. Their earliest condition has been that of 
 sand, clay, or carbonate of lime deposited from 
 water. 
 
 The unstratified and crystalline rocks are vari- 
 ously associated with the stratified rocks, and not 
 always below them. They are often seen breaking 
 up through the stratified masses, and penetrating 
 them in various ways. 
 
 Rocks are represented on the chart in five differ- 
 ent types. 
 
 (1.) The GRANITIC proper, including the great 
 central mass, and the granitic veins which penetrate 
 to the Silurian rocks. 
 
 (2.) The TRAPPEAN, including the porphyry dikes, 
 which, having their origin below, penetrate the 
 Gneissoid rocks, the Silurian, the Carboniferous, 
 and even the newer secondary strata ; and may be 
 found associated with the Tertiary rocks. These 
 have not only penetrated the strata from below, 
 but have sometimes flowed over the surface. 
 
 (3.) The VOLCANIC, which may penetrate any of 
 the strata, and, in a melted state, flow out over the 
 surface of the superficial beds. 
 
 (4.) The METAMORPHIC, which are shown next 
 above the Granite, as gneiss, mica slate, quartz 
 rocks, sandstones, crystalline limestones, &c. These 
 rocks, though evidently stratified, as if originally 
 
28 CLASSIFICATION AND ORIGIN 
 
 deposited from water, have become so altered by 
 igneous action, that their normal character is lost. 
 No fossil remains have ever been found in the rocks 
 of this period. 
 
 Beyond these, we find in the rocks of Silurian 
 age, gneiss, mica, and talcose slates, and crystalline 
 limestones, which are distinctly traceable to their 
 original conditions in the strata further to the right. 
 
 We have also on the left of the granite, strata of 
 the New Red Sandstone, Oolitic, and Cretaceous 
 formations, becoming metamorphic. 
 
 We thus perceive that though these rocks belong 
 to different parts of the stratified series, they are 
 nevertheless similarly changed by the same agencies, 
 the slates of any period becoming talcose and 
 mica slates, the sandstones becoming gneiss, the 
 gray, yellow, or blue limestones crystalline marble 
 of various colors. 
 
 (5.) The STRATIFIED or SEDIMENTARY rocks, 
 which, in their unaltered condition, occupy the 
 larger portion of the chart to the right hand, and 
 above those previously noticed. These rocks have 
 generally undergone no change from their original 
 condition of beds of mud, sand, and carbonate of 
 lime, except that in most cases they have become 
 indurated or stony in their character.* 
 
 * The student will understand the necessity of including all 
 deposits whatever as rocks, without regard to their condition of 
 
OF ROCK FORMATIONS. 29 
 
 These formations being altogether the most im- 
 portant and extensive, have been examined with 
 great care ; and from all the facts obtained, both 
 of their mineral character and contained fossils, 
 they have been arranged in subdivisions, as shown 
 on the chart. 
 
 This succession, as here given, represents the 
 order in which each one has been deposited above 
 the other ; and since each formation in turn has 
 been the uppermost, or the surface on which the 
 plants and animals have lived which are now found 
 imbedded in the rocks, they represent so many 
 epochs in the earth's history. Each one, even of 
 the minor subdivisions, represents what is equivalent 
 to a condition of the earth covered by its plants 
 and animals, as in its present actual condition. 
 In other words, were the entire present creation 
 to be destroyed and covered up by various sedi- 
 mentary deposits, the whole would represent, in 
 the continuation of the geological succession, only 
 one of the lesser subdivisions of any of the sys- 
 tems. 
 
 cohesion or induration, when he is told that the Potsdam Sand- 
 stone is, in many places, no more coherent or indurated than are 
 beds of sand or gravel of the latest periods ; and its condition, as 
 a stony or indurated rock, is by no means indicative of its age. 
 
 3* 
 
30 SILURIAN SYSTEM. 
 
 I. SILURIAN SYSTEM. 
 
 Above the system of Rocks designated as Meta- 
 morphic, commences a succession of stratified depos- 
 its, marked every where by the presence of fossils. 
 The first subdivision of this great series is known as 
 the SILURIAN SYSTEM. 
 
 From the great thickness of this system of rocks, 
 it has been found necessary to divide it into upper 
 and lower. The line of separation is marked, to a 
 great extent, in the United States, by a rock made 
 up of coarse sand and pebbles, or becoming in some 
 places a coarse sandstone. This subdivision is given 
 on the chart at the Oneida conglomerate. 
 
 In the United States, we recognize all the divis- 
 ions of the Silurian system given on the chart. 
 
 Characteristic Features of the Successive Beds.* 
 
 Potsdam Sandstone. This is the lowest member 
 of the Silurian system. It consists of an aggrega- 
 tion of water-worn sand, sometimes with pebbles 
 forming a conglomerate. The rock is usually com- 
 pact arid fine grained. 
 
 In its metamorphic condition, it becomes a com- 
 
 * The teacher should point out to the pupil these successive 
 rocks on the chart, as he reads these descriptions. He will also 
 find indicated some of the principal localities. 
 
SILURIAN SYSTEM. 31 
 
 pact, crystalline quartz rock, or, in some situations, 
 assumes the character of gneiss. 
 
 The principal fossils of this rock are two or more 
 species of Lingula. Some remains of trilobites and 
 other fossils have been found. 
 
 When compact, it is an excellent building stone. 
 
 Calciferous Sandstone. This rock usually consists 
 of a mixture of calcareous and siliceous particles, 
 whence it derives its name. It contains cavities 
 lined with quartz crystals, and has also layers or 
 nodules of chert, showing that the siliceous matter 
 has been in solution. At the west it is known as a 
 magnesian limestone, and is not very siliceous. 
 Some portions afford a hydraulic cement. 
 
 It breaks in rough, irregular blocks, and, except 
 in some of its localities, is fit only for a rough 
 building stone. 
 
 This rock contains quartz crystals, calcareous 
 spar, lead ore, and copper ore, and often small 
 nodules of anthracite coal. 
 
 The Chazy, Birds-eye, Black River, and Trenton 
 Limestones, form a group not always distinguished 
 from each other. They are, however, distinct, and 
 easily recognized by their fossils in the eastern part 
 of the United States. 
 
 Chazy Limestone, from the town of Chazy, on 
 Lake Champlain, where it is very well developed, 
 consists mainly of two members ; the lower is a 
 
32 SILURIAN SYSTEM. 
 
 light gray, and, for the most part, encrinal lime- 
 stone ; and the upper, a dark blue or nearly black 
 limestone. It occurs on both sides of Lake Cham- 
 plain, and upon the Isle la Motte, where it is exten- 
 sively quarried. 
 
 This rock contains no valuable minerals or metals. 
 
 When metamorphosed, it forms, with the succeed- 
 ing limestones, a crystalline marble. 
 
 Its fossils are numerous and characteristic. 
 
 The MacZurea, and other characteristic fossils, 
 being cut in various directions in the slabs of mar- 
 ble sawed from this rock, appear in great beauty. 
 It is largely used for flagging stones for the floors 
 of public buildings. 
 
 Birds-eye Limestone. This rock is of extremely 
 fine texture, of a light bluish color, weathering to a 
 drab or whitish ash color. It is even-bedded, readily 
 breaking into slabs, and very durable as a building 
 material ; it is extensively quarried along the Mo- 
 hawk valley and other places. 
 
 This name is derived from the appearance given 
 by numerous stems of a plant-like fossil, which pen- 
 etrate the layers vertically, as if the calcareous mud 
 had been deposited around them while growing ; 
 and when the surface is polished, the ends of these 
 stems present circular spots. 
 
 The principal fossils of this rock are the one 
 just mentioned, with a few corals and some cham- 
 bered shells. 
 
SILURIAN SYSTEM. 33 
 
 This rock can be traced westward for many 
 hundred miles, still retaining the same characters as 
 in New York. It is quarried at Frankfort, Ken- 
 tucky, where it is of a light ashen color. 
 
 Black River Limestone. This limestone is gray- 
 ish or bluish gray, coarser and less regularly bedded 
 than the Birds-eye. 
 
 Although a thin mass, it can be traced over a 
 wide extent of country, and is recognized by its fos- 
 sils as far west as the Mississippi River. 
 
 Its characteristic fossils are a coral and an Or- 
 moceras, (No. 63 on the chart.) 
 
 Trenton Limestone. This is a more important rock 
 than the three others preceding. It covers an ex- 
 tensive surface in the State of New York, particu- 
 larly along the valley of the Mohawk and its tribu- 
 taries, and in the valley of the Black River. It 
 forms the Trenton Falls, on West Canada Creek. 
 The rock is for the most part black or very dark, 
 thin-bedded or shaly, or with shale alternating with 
 thin bands of limestone. Many of the layers are 
 concretionary, or nodular, in structure. Some por- 
 tions are regularly bedded, and afford good building 
 stone ; the upper portion is often thick-bedded, of a 
 gray color, and crystalline in texture ; and this por- 
 tion especially furnishes an excellent building ma- 
 terial. 
 
 West of New York this rock becomes gradually 
 
34 SILURIAN SYSTEM. 
 
 thinner and lighter colored, and on the Mississippi 
 River consists of thin shaly layers, which weather 
 to a drab or ashen color. This limestone, with those 
 below it, are known to be continuous, from the west- 
 ern part of New England, in the direction of the 
 great lakes west and north-west, to beyond the Mis- 
 sissippi River, and south-west as far as Alabama. 
 
 The great valley of Virginia occurs in the lime- 
 stones of this period. 
 
 Fossils are extremely numerous in this rock, and 
 some of them extensively distributed and character- 
 istic, being found over many hundreds of miles in 
 extent. 
 
 The Trenton and other limestones of the Mohawk 
 valley are metamorphic east of the Hudson River, 
 becoming partially or entirely crystalline. These 
 are the white and variegated limestones of the west- 
 ern part of New England. 
 
 In an economical point of view, therefore, these 
 limestones are very important, furnishing excellent 
 building stones in their normal condition ; and again 
 in their metamorphism affording beautiful materials 
 for building, statuary, and ornament. 
 
 Hudson River Group. This group of strata con- 
 sists of shales, shaly sandstones, and sandstones, 
 with bands of impure limestone, and sometimes 
 thicker beds of limestone alternating with shale. 
 West of New York the calcareous matter increases 
 
SILURIAN SYSTEM. 35 
 
 in proportion, and the whole group becomes one of 
 shale and limestone, with no sandstone, and scarcely 
 any arenaceous shale. It thus becomes very differ- 
 ent at widely separated localities, and it is only by 
 studying intermediate points that we arrive at a 
 knowledge of the changes which gradually produce 
 these great differences.* 
 
 This group of rocks can be traced from the val- 
 ley of the Hudson River westwardly and north-west- 
 wardly, through the valley of the Mohawk to the 
 shores of Lake Ontario, and thence west through 
 Canada to the shores of Lake Huron, and even to 
 the northern shores of Lake Michigan. It also 
 covers a large area in Ohio, Indiana, Kentucky, and 
 Tennessee. 
 
 * The pupil should always recollect that a sedimentary deposit 
 will change in its character when extending 1 over a wide area. When 
 we consider the conditions under which such deposits are made, it is 
 easy to understand how this change is produced. Streams bring down 
 mixed sediment of sand and mud, and flow into an ocean where 
 the current is less ; consequently the heavier particles, no longer 
 suspended by the force of the stream, fall down. The finer mud 
 particles flow on, in very quiet water remaining some time sus- 
 pended, and, with a moderate current, will be carried to a great 
 distance. From this cause, shaly deposits will always be more 
 extensive than arenaceous deposits of the same period. This is 
 readily illustrated by the smallest stream flowing into a pond ; or it 
 may be illustrated by an artificial stream into which the pupil may 
 throw sand and mud, which, transported to a reservoir where the 
 current is checked, will be thrown down at different distances from 
 the inlet. 
 
36 SILURIAN SYSTEM. 
 
 In many parts of this extent it is highly fossil- 
 iferous, and the seas of tropical climates of the 
 present day scarcely any where furnish a more nu- 
 merous and varied fauna than these very ancient 
 strata. 
 
 The rocks of this group, when metamorphic, pro- 
 duce chloritic, talcose, and mica slates, as shown in 
 the chart, towards the granitic peak. 
 
 Oneida Conglomerate, or Shawangunk Grit. This 
 rock is a coarse sandstone or conglomerate, resting 
 upon the Hudson River group, and from which there 
 is someti.nes a gradual passage. It forms the line 
 of division between the Lower and Upper Silurian. 
 In many places this rock does not exist, having 
 thinned out ; and the Medina sandstone rests upon 
 the sandstones or the terminating calcareous beds of 
 the Hudson River group. 
 
 This rock is used for millstones, and the Esopus 
 millstones are made from it. It forms the Shawan- 
 gunk Mountain, in New York, and the continuation 
 of the same range in New Jersey. It received the 
 name of Oneida conglomerate from its occurrence 
 in Oneida county, being the only conglomerate rock 
 in that part of the State of New York. It there 
 rests conspicuously on the rocks of the Hudson 
 River ; and the Medina sandstone being absent, it is 
 succeeded by the Clinton group. 
 
 Medina Sandstone. This is a red or brownish, 
 
SILURIAN SYSTEM. 37 
 
 argillaceous sandstone, usually soft and readily dis- 
 integrating on exposure. Some portions are more 
 siliceous, and, furnish good building stone. It is a 
 conspicuous rock at Medina, Orleans county, New 
 York, the canal being cut through it for some distance. 
 It forms the lower fall on the Genesee River, and the 
 banks of the river to its mouth. It also forms the 
 banks of the Niagara River at Lewiston, and a part 
 of the cliff on either side for several miles above. 
 In the eastern part of New York, it thins out, and 
 is hardly recognizable. 
 
 It contains few organic remains ; the most im- 
 portant are a species of Lingula and a marine 
 plant. 
 
 Clinton Group. This consists of shales, sand- 
 stones, conglomerates, limestones, and beds of iron- 
 ore. Although of moderate thickness,, it extend* 
 throughout the State of New York, occurs in Can- 
 ada, and again upon the shores of Lake Huron and 
 Lake Michigan. 
 
 The most important feature of this group, in an- 
 economical point of view, are the beds of iron ore* 
 which are coextensive with the strata, and uniform 
 for a hundred miles. 
 
 Niagara Group. This consists mainly of a mags 
 of shale, and another of limestone above. The 
 limestone forms the table-rock over which the Niag- 
 ara River falls, and the shale below is the rock 
 4 
 
38 SILURIAN SYSTEM. 
 
 which is worn away by the action of the water and 
 air. 
 
 The shale is soft and argillaceous, consisting 
 mostly of clay, with a small proportion of lime. It 
 contains iron pyrites, which decomposes on expo- 
 sure, causing the rock to crumble rapidly. The 
 limestone, on the contrary, is extremely durable, 
 withstanding the effects of weather. It forms one 
 of the best building stones in New York. The lower 
 part, which is filled with the stems of encrinites, has 
 been used for the beautiful series of locks at Lock- 
 port. The fragments of crinoids are often brown 
 or reddish. 
 
 West of New York, the shale of this group be- 
 comes more calcareous, and finally the whole mass 
 is a limestone. It extends from Niagara westward 
 through Canada, along Lake Huron and Lake Mich- 
 igan, and thence to the Mississippi River. 
 
 It has many beautiful and characteristic fossils ; 
 and by the presence of a certain coral, (fig. 10,) it 
 can be traced over hundreds of miles across the west- 
 ern mounds and prairies. 
 
 Onondaga Salt Group. This group consists of 
 shaly and marly deposits, composed of clay, and 
 carbonate and magnesian carbonate of lime. The 
 lower part is a red shale ; the middle and upper parts 
 are gray, greenish gray, and ashen colored. 
 
 In the State of New York it is chiefly important 
 
SILURIAN SYSTEM. 39 
 
 from its brine springs. These are principally con- 
 fined to the valley of the Onondaga Lake, whence the 
 name of the group. All the gypsum of New York, 
 of any importance, is derived from these rocks. 
 
 Tracing the group eastward from Onondaga 
 Lake, it thins out on the Hudson River, and west- 
 wardly becomes more calcareous, and finally it is 
 not distinctly recognizable beyond the shore of Lake 
 Michigan. 
 
 The soils formed from the decomposition of the 
 rocks of this group, and of those of the Niagara 
 group, are among the most fertile in the United 
 States. 
 
 Lower Helderberg Limestones. These limestones 
 have been described as the water lime or Tentacu- 
 lite limestone, the Pcntamerus galeatus limestone, the 
 Delthyris shaly limestone, the Encrinal limestone, 
 and the Upper Pentamerus limestone. Although 
 each of these rocks is distinct and well marked in 
 New York, they are not so easily distinguished indi- 
 vidually elsewhere. The lower, first named, are 
 dark colored and thin-bedded limestones ; the next 
 are thick-bedded, gray or bluish ; the third a shaly 
 limestone, and the two upper gray and crystal- 
 line. 
 
 In a westerly direction, these limestones thin out 
 entirely ; and, from the thinning of the Oriskany 
 sandstone above them, the Upper Helderberg lime- 
 
40 DEVONIAN SYSTEM. 
 
 stones rest upon the Onondaga Salt group, as shown 
 on the chart at the right of the Trap dike. South- 
 ward they extend through Pennsylvania, Virginia, 
 and Tennessee, where, from the absence of the 
 Onondaga Salt group, they rest directly upon the 
 Niagara group, and the fossils of the two are often 
 mingled together. 
 
 II. DEVONIAN SYSTEM. OrisJcany Sandstone. This 
 rock succeeds the Lower Helderberg limestones. It 
 is a friable, or sometimes calcareous sandstone, from 
 which much calcareous matter has been removed by 
 water. In other places, the rock appears to be a 
 compound of lime and silex deposited from solution. 
 In some parts it abounds in fossil shells, but in most 
 localities the shell has been removed, and casts 
 only remain. When the sedimentary deposit is 
 coarser, and more readily penetrated by water, 
 the forms of the shells have entirely disappeared, 
 and cavities or shapeless casts alone remain. This 
 rock forms the separation between the Silurian 
 and Devonian systems, as now recognized in this 
 country. 
 
 Cauda-galli Grit. This deposit succeeds the Oris- 
 kany sandstone. It is composed of a mixture of 
 shaly or clayey matter and sand, crumbling down 
 into angular fragments on exposure to the air. It 
 is a dark-colored rock, weathering to a rusty brown, 
 and contains no fossils, unless, perhaps, a marine 
 
DEVONIAN SYSTEM. 41 
 
 plant, which produces very curious markings upon 
 its surface, from which this name has been 
 given. 
 
 Upper Helderberg Limestones. Included under this 
 head are the Schoharie grit, and the Onondaga and 
 Corniferous limestones. The whole together form a 
 group, coextensive with the Palaeozoic deposits in 
 the United States. They can be traced from the 
 Helderberg Mountains, and their continuation on the 
 Hudson River, westwardly to the Niagara River at 
 Black Rock ; and thence through Canada, and 
 across the Detroit River into Michigan : and also on 
 the south side of Lake Erie, through Ohio, Indiana, 
 Illinois, and Kentucky. 
 
 The limestones are gray, bluish, and black, the 
 higher one containing much chert or hornstone. 
 They every where are filled with great numbers of 
 fossils, among which have been found remains of 
 large fishes. 
 
 Hamilton Group. This consists of a series of 
 shales. These have been distinguished as the Mar- 
 cellus slate, which is black and slaty ; the Ludlmo- 
 ville shales, more fissile, and of an olive color ; the 
 Moscow shale, which is bluish or grayish blue, and 
 very fissile. 
 
 In the central and eastern parts of New York, 
 this group contains large proportions of arenaceous 
 shales and shaly sandstones. The subdivisions are 
 4* 
 
42 DEVONIAN SYSTEM. 
 
 not in all places conspicuous, and where the arena- 
 ceous deposits prevail, none can be distinguished ex- 
 cept the lower black slate or Marcellus, which al- 
 ways retains its characters. The group occupies a 
 thickness of some eight hundred or one thousand 
 feet. It extends through New York, a part of 
 Pennsylvania, Ohio, Canada West, and Michigan. 
 
 In the number and beauty of its fossils, it exceeds 
 any of the other groups, several hundred species 
 being already known in the State of New York 
 alone. 
 
 The Tully Limestone. This may be regarded as a 
 subordinate member of the preceding group. It is 
 a mass of shaly limestone, twenty to fifty feet thick. 
 It contains some fossils not known in the Hamilton 
 group, the most peculiar of which is the Atrypa 
 cuboides. 
 
 Genesee Slate. This is a black, fissile rock, split- 
 ting in thin, even laminae, and nearly destitute of 
 fossils. It holds a very conspicuous position, form- 
 ing the junction between the calcareous shales be- 
 low, and the argillaceous shales and shaly sandstones 
 
 A 
 
 destitute of lime, above. There is also, beyond this 
 point, an almost entire change in the fossils. 
 
 Portage Group. This is so named from the 
 rocks exposed in the three successive falls at Port- 
 age, and in the banks of the Genesee River below. 
 It consists of a series of shales and shaly sandstones, 
 
DEVONIAN SYSTEM. 43 
 
 nearly destitute of calcareous matter, and contain- 
 ing few fossils. 
 
 This group has been described as consisting of 
 three members : 1. The Cashaqua Shale, a soft, 
 green shale, with nodules of a semi-calcareous rock, 
 or shaly sandstone ; 2. The Garckau Flagstones, 
 which are compact and firm shaly sandstones; 
 3. The Portage Sandstones, consisting of thin and 
 thick-bedded argillaceous sandstones, which crumble 
 on exposure to the air. 
 
 This group is very conspicuous in the western 
 part of New York, and is seen along the shore of 
 Lake Erie from below Dunkirk, westward beyond 
 the eastern limits of Ohio. 
 
 Chemung Group. This consists of a series of 
 shales, shaly sandstones, and sandstones, all of which 
 are olive or greenish in color. Almost the only cal- 
 careous matter in this group is derived from the re- 
 mains of shells. It is equally thick as the preceding 
 group, and occupies a large extent of surface, a 
 width of twenty or thirty miles .in the southern coun- 
 ties of New York. Towards the east, it resembles 
 the Hamilton group in its appearance, though the 
 fossils are quite different. Beyond the limits of 
 New York, it may be traced west into Ohio. 
 
 It contains few materials of economical value. 
 Its fossils are numerous, and partake of the char- 
 
14 DEVONIAN SYSTEM. 
 
 acters of those usually considered as characterizing 
 rocks of the Carboniferous age. 
 
 Old Red Sandstone, or Catskill Mountain Group. 
 Above the Chemung Group, we usually find some 
 coarser beds of sandstone or a conglomerate ; and 
 still beyond, a series of micaceous shales and shaly 
 sandstones of great thickness. These rocks are 
 mostly brown or reddish, and, where not exposed, 
 sometimes green. They are conspicuous as form- 
 ing the high Catskill Mountains. This series has 
 been regarded as the equivalent of the Old Red 
 Sandstone of Europe ; and the opinion was con- 
 firmed by the discovery of the remains of several 
 fishes characteristic of that rock. The fish scale 
 (fig. 167 ) on the chart is from this. 
 
 Notwithstanding the great thickness of this group 
 in the Catskill Mountains, it thins out rapidly west ; 
 and while on the Chemung River, within the bor- 
 ders of Pennsylvania, the whole group is several 
 hundred feet in thickness, on the Genesee River, at 
 the southern limits of New York, it is but a few feet 
 thick. This circumstance, with the horizontal po- 
 sition of the strata, render the rock interesting and 
 remarkable ; and it is evident that during its depo- 
 sition there must have been repeated sinkings of the 
 bed of the ocean, to allow of this great accumula- 
 tion in the limited area which it occupies. 
 
CARBONIFEROUS SYSTEM. 45 
 
 III. CARBONIFEROUS SYSTEM. This system em- 
 braces a series of shales and sandstones ; an exten- 
 sive limestone formation ; a second series of various 
 colored shales, sandstones, and conglomerates ; and, 
 following these, beds of shale and sandstone, with 
 beds of coal. This latter part of the series has given 
 the designation to the whole. The shales, sandstones, 
 and limestones contain remains of shells, corals, and 
 fishes, showing their marine origin ; while the coal 
 has resulted from terrestrial vegetation, and the re- 
 mains of land plants are every where imbedded in 
 the shales and sandstones which accompany the coal. 
 The following are the subdivisions : 
 
 1. Yellow Sandstones and Shales. ( Waverly Sand- 
 stones.) The lowest group of strata recognized as 
 belonging to the Carboniferous period, are the yel- 
 low sandstones and shales which are very widely 
 distributed in Ohio, Indiana, and Kentucky. These 
 contain, in places, some thin beds of limestone. 
 Fossil shells are abundant in the sandstones, and 
 great numbers of crinoids are found in the shales. 
 
 In the Geological Reports of Ohio, these sand- 
 stones in part are described as the Waverly sand- 
 stones ; and from the absence of the intervening 
 rocks, these strata have not always been distinguished 
 from the Chemung and Portage groups. 
 
 2. Carboniferous Limestone. This great limestone 
 formation underlies the coal strata throughout most 
 
46 CARBONIFEROUS SYSTEM. 
 
 of their extent. It is in great part a gray, or bluish 
 gray limestone, weathering to a light ashen color. 
 Some parts of it are crystalline, others compact and 
 fine grained, and some of the strata are Oolitic in 
 structure. 
 
 This limestone has a great thickness and extent 
 in the Western States. It is very conspicuous along 
 the Mississippi River, forming high cliffs above the 
 mouth of the Ohio. It is also the rock in which all 
 the large caves of the west occur; the Mammoth 
 Cave, in Kentucky, and others of great extent in 
 Indiana, are in this rock. It contains numerous fos- 
 sil shells and corals ; among the latter, one very re- 
 markable and interesting form is represented on the 
 chart, in figures 134 and 135. 
 
 3. Red Shales and Shaly Sandstones. Succeeding 
 the limestone just described, there are, in some parts 
 of the country, a series of red and brown shales 
 and sandstones. These lie below the great con- 
 glomerate which is directly at the base of the Coal 
 measures. In the eastern coal fields, these rocks 
 are important, and form a conspicuous feature in the 
 landscape ; while at the west, their existence is 
 scarcely recognized. 
 
 Carboniferous Conglomerate, or Millstone Grit. 
 Throughout Pennsylvania, Ohio, and in some parts 
 of Indiana and Kentucky, this coarse conglomerate 
 lies at the base of the coal-bearing rocks. It 
 
CARBONIFEROUS SYSTEM. 47 
 
 corresponds apparently with the Millstone grit of 
 the European Coal measures. It is composed of 
 coarse sand and pebbles of crystalline quartz, often 
 scarcely cohering. It forms a prominent horizon in 
 the neighborhood of the outcropping Coal measures, 
 and an excellent guide in searching for beds of coal. 
 
 Great Coal Measures, or Coal Formation Proper. 
 This consists of a series of beds of soft shale, sand- 
 stone, conglomerate, and beds of coal, with, more 
 rarely, beds of limestone. There is no regular suc- 
 cession throughout the whole, but repeated alterna- 
 tions of beds such as enumerated. In the coal fields 
 of Pennsylvania, more than twenty successive beds 
 of coal are known, separated from each other by 
 beds of shale and sandstone. 
 
 The coal has all been formed from the decompo- 
 sition of vegetable matter ; and remains of numer- 
 ous plants are found in the shale above the beds of 
 coal, and in the under clay" or soft shale underly- 
 ing the coal bed, as well as in the coal itself. 
 The fossil plants at the base are likewise different 
 from those in the shale above, which, together with 
 the condition of the material, ( showing quiet depo- 
 sition, leads us to infer that these deposits were made , 
 in quiet water, and that the plants grew and were 
 imbedded where we now find them. Moreover, the 
 successive beds of coal are characterized by different 
 species of ferns which undoubtedly grew at that 
 
CARBONIFEROUS SYSTEM. 
 
 period, and show from their perfect preservation that 
 they suffered little disturbance before being imbedded 
 in the mud. 
 
 The importance of this formation can scarcely be 
 overrated. It furnishes all our coal, both anthracite 
 and bituminous, and iron ore in large quantities is 
 also associated with the coal beds. The sandstones 
 afford good building material ; and while some of 
 the limestones furnish lime, others are fit for archi- 
 tectural and ornamental purposes. The coal serves 
 us as fuel, fuses our ores, generates the steam for 
 our manufactories and steamboats, and is in fact the 
 controlling element in our mechanical, manufactur- 
 ing, and , commercial operations. 
 
 The extent of the coal fields in the United States 
 is greater than in all the rest of the known world ; 
 and they are so situated as to give the greatest pos- 
 sible facilities for mining and transportation. 
 
 The series of strata from the base of the strati- 
 fied rocks to the top of the Coal measures, is very 
 perfect in the United States ; but above this the se- 
 ries is very incomplete.* 
 
 * The preceding rocks being more important to the American 
 student in geology, from forming an essential part of the geologi- 
 cal structure of the United States, have been mentioned in detail. 
 For the remainder of the series, which are but imperfectly devel- 
 oped, or exist only in representative beds or parts of great groups, 
 a general description only will be given. 
 
NEW RED SANDSTONE. 49 
 
 IV. NEW- RED SANDSTONE SYSTEM. PERMIAN 
 AND TRIASSIC SYSTEMS. Above the Coal measures, 
 and overlying them, sometimes conformably, and at 
 other times unconformably, is found a series of red 
 sandstones, red, green, and variegated shales, marls, 
 and sandstones, with yellow magnesian limestones. 
 These contain few traces of vegetation, and the 
 organic remains are quite distinct from those in the 
 rocks below. The system has been divided into 
 Permian and Triassic systems. 
 
 The rocks recognized as of the New Red Sand- 
 stone period, are the sandstones and shales of the 
 Connecticut River valley, New Jersey, Virginia, and 
 North Carolina. These belong apparently to the 
 Triassic System, and represent a portion of the 
 upper marls and sandstones of the period, as more 
 fully developed in Europe. The remains of fishes, 
 and the tracks of birds, which have been so beauti- 
 fully developed and illustrated by Professor Hitch- 
 cock, Dr. Deane, Mr. Redfield, and Mr. Marsh, are 
 among the interesting fossil remains of this period 
 in the United States. 
 
 It will be observed that no American localities are 
 given upon the chart for any of the strata of the 
 Permian system, none of its members having yet 
 been found in this .country. 
 
 In England, and upon the continent of Europe, 
 gypsum and rock salt are found in the marls and 
 5 
 
50 OOLITIC SYSTEM. 
 
 sandstones of the higher part (Triassic) of the sys- 
 tem ; and hence the name saliferous, or salt-bearing. 
 
 Both in this country and in Europe, the rocks of 
 this age are associated with igneous rocks, which, 
 penetrating the coal formation, pass through and be- 
 tween the layers of sandstone and shale, and finally 
 in many places overlie the whole, in vast masses of 
 basaltic rocks. Examples of this are seen in the 
 Connecticut valley, Mount Holyoke, the East and 
 West hills, near New Haven, and the Palisades, 
 along the Hudson River. 
 
 V. OOLITIC SYSTEM. The several members of 
 this system are of more or less importance in Eng- 
 land and upon the continent of Europe. The only 
 member recognized in the United States is a forma- 
 tion at Richmond, Virginia, which appears to be a 
 representative of the Lias of Europe. 
 
 The system consists of limestones and shales. A 
 soft bituminous coal is associated with it, and the 
 shale contains remains of numerous ferns and other 
 plants. The limestones have not the compact struc- 
 ture of those in the Palaeozoic rocks, arid they are 
 often intermixed with clays and sands, and the layers 
 separated by shaly or arenaceous beds. 
 
 This period is remarkable for the appearance of 
 large marine reptiles. The contrast in the general 
 features of the fossils of the Permian, Triassic, and 
 Oolitic systems, with the preceding, is very appa- 
 rent. 
 
CRETACEOUS AND TERTIARY SYSTEMS. 51 
 
 la Europe, the limestones of this period furnish 
 
 beautiful marble ; and the fine statuary marble, so 
 long regarded as Primary, is a metamorphic lime- 
 stone of this age. 
 
 VI. CRETACEOUS SYSTEM. The characteristic 
 feature of this system is the existence of extensive 
 strata of chalk. The subdivisions include the Weal- 
 den and Neocomien groups, both of which are local ; 
 the former being scarcely known out of England, and 
 the latter being only recognized on the continent of 
 Europe. Beyond these, we notice three stages in 
 the Cretaceous system : the Green sand, upper 
 and lower, with the gault or chalk marl ; the Lower 
 chalk, and the Upper chalk, with the Pisolite or 
 Maestricht beds. 
 
 The lower and middle portions of this system are 
 represented in the United States, east of the Missis- 
 sippi River only by the Green sand of New Jersey 
 and some of the Southern States. West of the Mis- 
 sissippi River, and towards the base of the Rocky 
 Mountains, the Cretaceous system is very extensive, 
 reaching from north of the Missouri River south- 
 west into Texas. 
 
 The fossils of this system represented on the chart, 
 are characteristic both in America and Europe. 
 
 VII. TERTIARY SYSTEM. This consists of three 
 distinct groups, representing distinct periods of depo- 
 sition. These are the Eocene, Miocene, and Pliocene. 
 
52 QUATERNARY PERIOD. 
 
 The Eocene formation in the United States con- 
 sists of beds of green sand, yellow limestone, and 
 admixtures of clay and sand. 
 
 London clay and the coarse limestones of Paris 
 belong to this period. 
 
 The Miocene, or Middle Tertiary, in the United 
 States, consists of various sands and clays. 
 
 These older Tertiary formations extend from 
 Maryland through Virginia, North and South Caro- 
 lina, Georgia, Alabama, Louisiana, and Mississippi. 
 They are characterized by immense numbers of 
 shells, and also by the remains of sharks, and sev- 
 eral peculiar species of cetaceans. 
 
 The Pliocene formation has not been clearly 
 recognized in the United States. The Norfolk crag 
 of England, the sub-Appenine beds of Southern 
 Europe, and extensive deposits in Sicily, belong to 
 this period. 
 
 VIII. MODERN OR QUATERNARY PERIOD. Drift. 
 Succeeding the Tertiary deposits proper, is the 
 period of the Drift. This term is applied to super- 
 ficial materials, consisting of sand, gravel, clay, peb- 
 bles, and boulders, whether deposited from water, 
 and thus assorted and stratified, or mingled together 
 without order or stratification, bearing evidence of 
 having been transported by other means than water. 
 
 The source from which the drift and all other 
 superficial deposits are derived, is the older rock 
 
QUATERNARY PERIOD. 53 
 
 formations which have been broken up and more or 
 less comminuted by the action of water and the 
 fragments among themselves. Owing to this cir- 
 cumstance, a single rock formation or group of 
 strata has, by the breaking up and transportation of 
 its broken materials, formed the superficial deposits 
 over wide areas, and thus given origin to the soils, 
 and consequently the vegetation, of the surface. 
 5* 
 
LIST OF FOSSILS 
 
 FIGURED UPON THE CHART* 
 I. PALAEOZOIC FOSSILS, 
 
 IN CLUDING 
 
 LOWER AND UPPER SILURIAN, DEVONIAN, AND 
 CARBONIFEROUS. 
 
 
 Fig. 1. Buthotrephis gracilis. Clinton Group. Onei- 
 da county, New York. 
 
 Fig. 2. Chsetetes Lycoperdon. Trenton Limestone 
 and Hudson River Group. Trenton Falls, Mohawk val- 
 ley, New York ; Cincinnati, Maysville, and many other 
 localities at the West. 
 
 Fig. 3. Streptelasma corniculum. Trenton Lime- 
 stone. Trenton Falls, New York ; Ohio, Wisconsin, and 
 Tennessee. 
 
 Fig. 4. Favistella stcllata. Hudson River Group. 
 Madison, Indiana ; Nashville, Tennessee; Drummond's 
 Island. 
 
 Fig. 5. Graptolithus ramosus. Hudson River Group. 
 Albany, New York. 
 
 * The name of the fossil is first given, and following 1 it the name 
 of the particular rock or group, and lastly the name of one or 
 more localities. 
 
LIST OF FOSSILS. 55 
 
 Fig. 6. Graptolithus pristis. Hudson River Group. 
 Mohawk and Hudson River valleys. 
 
 Fig. 7. Stictopora ramosa. Trenton Limestone. Mid- 
 dleville and Trenton Falls, New York. 
 
 Fig. 8. Conophyllum Niagarense. Niagara Group. 
 Lockport, New York. 
 
 Fig. 9. Camilla Helderbergiae. Delthyris Shaty Lime- 
 stone. Base of Helderberg Mountain, Albany county, 
 New York. 
 
 Fig. 10. Catenipora escharoides. Niagara Lime- 
 stone, and Clinton Groups. Western New York, Wis- 
 consin, Iowa, Kentucky, &c. 
 
 Fig. 11. Heterocrinus simplex. Blue Limestone, (age 
 of Hudson River Group.) Ohio, Indiana, and Tennessee. 
 
 Fig. 12. Glyptocrinus dodeka-dactylus. Hudson 
 River Group. New York. "Blue Limestone," Cincin- 
 nati, Ohio. 
 
 Fig. 13. Ichthyocrinus la-vis. Shale of the Niagara 
 Group. Lockport, New York ; also in limestones of Ten- 
 nessee. 
 
 Fig. 14. Dendrocrinus longidactylus* Niagara 
 Group. Lockport, New York. 
 
 Fig. 15. Encalyptocrinus (Hypanthocrinus] decorus. 
 Shale of the Niagara Group. New York and Tennessee. 
 
 Fig. 1C. Caryocrinus ornatus. Niagara Group. 
 New York and Tennessee. 
 
 Fig. 17. Caryocrinus ornatus. A young specimen, 
 with a portion of the arms attached. 
 
 Fig. 18. A part of the column and root of the same. 
 This species occurs, in the Niagara Group, at Rochester 
 and Lockport, New York ; Glades of Decatur county, Ten- 
 nessee. 
 
 Fig. 19. Callocystites Jewettii. Niagara Shale. 
 Lockport, New York. 
 
 Fig. 20. Lepadocrinus Gebhardii. Pent amcrus go- 
 
56 INTRODUCTION. 
 
 leatus Limestone, (of Lower Helderberg limestones.) Hel- 
 derberg Mountains and Schoharie. 
 
 Fig. 21. Joints of the column of the same. The figure 
 between this and fig. 20 is a single plate of the body. 
 
 Fig. 22. Palaeaster (dsterias) matutina. This is an 
 ancient representative of the modern star fishes. Trenton 
 Limestone. New York. 
 
 Fig. 23. Schizocrinus nodosns. Structure of the body 
 and arms, in part. Trenton Limestone. New York. 
 
 Fig. 24. Part of an arm of the same, with the plates 
 and tentaculse attached. 
 
 Fig. 25. Homocrinus. Structure of the body. Tren- 
 ton Limestone. Mohawk valley, New York. 
 
 Fig. 26. JLiiigula prima. Potsdam Sandstone. New 
 York, St. Croix, and Wisconsin Rivers. 
 
 Fig. 27. Lingnla quadrata. Trenton Limestone and 
 Hudson River Group. New York, Ohio, Wisconsin, and 
 Iowa ; also in Lower Silurian rocks in Europe. 
 
 Fig. 28. Orthis calligramma. Lower Silurian rocks 
 of Europe. 
 
 Fig. 29. Orthis testudinaria. Trenton Limestone 
 and Hudson River Group. New York and Ohio. 
 
 Fig. 30. Orthis plicatella. Trenton Limestone. New 
 York. Blue Limestone. Ohio. 
 
 Fig. 31. Orthis tricenaria. Trenton Limestone. New 
 York, Wisconsin, Iowa, Tennessee, &c. 
 
 Fig. 32. Orthis flabelulum. Niagara Group. Roch- 
 ester, Lockport, &c., New York. 
 
 Fig. 33. Leptaena alternata. Trenton Limestone and 
 Hudson River Group. Middleville, Trenton Falls, Low- 
 ville, Watertown, &c., New York ; Cincinnati, Ohio ; Mad- 
 ison, Indiana ; Maysville, Kentucky ; Nashville, Tennes- 
 see ; near Galena, Plattville, and Mineral Point, Wiscon- 
 sin ; Illinois ; Dubuque, Iowa ; Falls of St. Anthony. 
 
 Fig. 34. Leptaena filitexta. Trenton Limestone. New 
 
LIST OF FOSSILS. 57 
 
 York. Lower part of Blue Limestone, in Tennessee, Ohio, 
 Wisconsin. 
 
 Fig. 35. Leptaena depressa. Niagara Group, Low- 
 er and Upper Helderberg Limestones. New York. 
 
 Fig. 36. Spirifer lynx. Trenton Limestone and Hud- 
 son River Group. New York, Ohio, Kentucky, &c. 
 
 Fig. 36 a. Smaller variety of the same. 
 
 Fig. 37. Spirifer Niagarensis. Niagara Group. Wol- 
 cott, Rochester, Lockport, and other places in New 
 York. 
 
 Fig. 38. Spirifer rugosa. Lower Helderberg Lime- 
 stones. Base of Helderberg Mountains, Schoharie, Car- 
 lisle, and other places, New York ; Pennsylvania, Virginia, 
 and glades of Decatur county, Tennessee. 
 
 Fig. 39. Spirifer varica. Delthyris Shaly Limestone. 
 Base of the Helderberg Mountains, New York. 
 
 Fig. 40. Spirifer macropleura. Delthyris Shaly Lime- 
 stone. Base of Helderberg Mountains, New York, Penn- 
 sylvania, Virginia, and Tennessee. 
 
 Figs. 41, 42, and 43. Atrypa increbescens. Trenton 
 Limestone and Hudson River Group. Blue Limestone of 
 the West. Trenton Falls, Middleville, and other places, 
 New York ; Cincinnati, Ohio ; Maysville, Kentucky ; Mad- 
 ison, Indiana ; Nashville, Tennessee ; and other western 
 localities. The species is remarkably variable in size and 
 proportions, depending on age and other circumstances. 
 
 Fig. 44. Atrypa reticulata. Niagara, Lower and 
 Upper Helderberg Limestones, and Hamilton Group. Lock- 
 port, New York, Helderberg Mountains, Genesee valley, 
 Eighteen Mile Creek, Lake Erie, and numerous western 
 localities. 
 
 Fig. 45. Atrypa aequiradiata. Upper Member of the 
 Lower Helderberg limestones. Helderberg Mountains and 
 Schoharie. 
 
 Fig. 46. Pentamerus galeatiis. Pentamerus Lime- 
 
58 INTRODUCTION. 
 
 stone. Helderberg Mountains and Schoharie, New York ; 
 Pennsylvania, Virginia, and Tennessee. 
 
 Fig. 47. Pentamerus oblongus. Clinton Group. Near 
 Rochester and Wolcott, New York. Limestone of Niagara 
 Group. Wisconsin, Illinois, Iowa, Kentucky, and Ten- 
 nessee. 
 
 Fig. 48.* Cast of Pentamerus oblongus. This spe- 
 cies occurs in the condition of casts in most of the western 
 localities. 
 
 Fig. 49. Atrypa obesa. Upper Pentamerus Lime- 
 stone. Base of the Helderberg Mountains. 
 
 Fig. 50. Ambonychia [Pterinia] radiata. Hudson 
 River Group. Oswego and Lewis counties, New York; 
 shore of Little Bay des Noquets, Madison, Indiana ; Cincin- 
 nati, Ohio. 
 
 Fig. 51. Modiolopsis modiolaris. Hudson River 
 Group. Same localities as the preceding species. 
 
 Fig. 52. Avicula. Lower Helderberg Limestones. Hel- 
 derberg Mountains, New York. 
 
 Fig. 53. Avicula. Lower Helderberg Limestones. Hel- 
 derberg Mountains, Schoharie, Catskill. 
 
 Fig. 54. Murchisonia bellacincta. Trenton Lime- 
 stone. Middleville, Trenton Falls, Lowville, and Water- 
 town, New York ; Ohio, Indiana, Kentucky, and Tennessee. 
 
 Fig. 55. Murchisonia bicincta. Black River and 
 Trenton Limestones. Trenton Falls, Middleville, and 
 Watertown, New York ; Wisconsin, Tennessee. 
 
 Fig. 56. Acroculia acuminata. Delthyris Shaly Lime- 
 stone. Helderberg Mountains and Schoharie, New York. 
 
 Fig. 57. Acroculia Gebhardii. Same position and 
 localities as the preceding species. 
 
 Fig. 58. Platyostoma ventricosa. Same position and 
 localities as the preceding. 
 
 * On a few copies of the ohart it is marked 18, but is known 
 by being 1 the next figure to the right of 47. 
 
LIST OF FOSSILS. 59 
 
 Fig. 59. Cyrtolites ornatus. Hudson River Group. 
 Oswego and Lewis counties, New York. In the same 
 geological position in Ohio, Indiana, and Tennessee. 
 
 Fig. 60. Bellerophon bilobatus. Trenton Limestone 
 and Hudson River Group. New York, Ohio, Indiana, 
 Kentucky, Wisconsin, and Iowa. 
 
 Fig. 61. Trocholites ammonius. Trenton Limestone. 
 Middleville, New York. 
 
 Fig. 62. Orthoceras multacameratum. Birds-eye 
 Limestone. Black River valley, New York ; Tennessee. 
 
 Fig. 63. Ormoceras tenuifilum. Black River Lime- 
 stone. Watertown, New York ; Northern Michigan, Wis- 
 consin, and Tennessee. 
 
 Fig. 64. Endoceras proteiforme. Trenton Limestone. 
 Middleville and Trenton Falls, New York ; Northern Mich- 
 igan, and Tennessee. 
 
 Fig. 65. Beyrichia tuberculata. Upper Silurian 
 strata of England. (This form of crustacean is usually 
 known as Jlgnostus.) 
 
 Fig. 66. Cytherina fabulites. Upper part of Birds- 
 eye^ and in Black River Limestone. Watertown, New 
 York ; Mineral Point, Wisconsin, and in Tennessee. 
 
 Fig. 67. Cytherina spinosa. (The position of the 
 valve reversed.) Niagara Group. Lockport, New York. 
 
 Fig. 68. Agnostus integer. Silurian rocks of Bo- 
 hemia. 
 
 Fig. 69. Trinucleus concentricus. Trenton Lime- 
 stone and Hudson River Group. Glen's Falls, Trenton 
 Falls, Oswego, Lewis, and Jefferson counties, New York ; 
 Cincinnati, Ohio, and other western localities. 
 
 Fig. 70. Calymene (Triarthrus) Beckii. Trenton 
 Limestone, Utica Slate and Hudson River Group. Mohawk 
 valley, Turin, in Lewis county, New York ; Cincinnati, 
 Ohio. 
 
 Fig. 71. Isotelus gigas. Trenton Limestow Tren- 
 
60 INTRODUCTION. 
 
 ton Falls, Middleville, Watertown, and Sacket's Harbor, 
 New York ; Cincinnati, Ohio. 
 
 Fig. 72. Illaenus crassicauda. Trenton Limestone, 
 and other Lower Silurian strata. Trenton Falls, Water- 
 town, &c., New York. 
 
 Fig. 73. Ceraurus pleurexanthemus. Trenton Lime- 
 stone. Trenton Falls, Middleville, and Watertown, New 
 York ; Cincinnati, Ohio ; Tennessee. 
 
 Fig. 74. Homalonotns delphinocephalus. Niagara 
 Group. Rochester and Lockport, New York. 
 
 Fig. 75. Phacops limulnrus. Niagara Group. Roch- 
 ester and Lockport, New York. 
 
 Fig. 76. Calymene Blumenbachii, var. Niagarensis. 
 Niagara Group. Wolcott, Rochester, and Lockport, New 
 York. 
 
 Fig. 77. Lichas (Platynotus) Boltoni. Niagara 
 Group. Lockport, New York. 
 
 Fig. 78. Phacops nasutus. Delihyris Shaty lAme- 
 stone. Base of Helderberg Mountains and Schoharie, New 
 York. 
 
 Fig. 79. Acidaspis elliptica. Silurian rocks. Eu- 
 rope. A similar species (in fragments) occurs in the Lower 
 Helderberg limestones. 
 
 Fig. 80. Phacops Hausmanii. Lower Helderberg 
 Limestones. Base of Helderberg Mountains and Scho- 
 harie, New York ; near Rumsey, Virginia, and in Ten- 
 nessee. 
 
 Fig. 81. Eurypteris remipes. Onondaga Salt Group- 
 Waterville and Williamsville, New York. 
 
 Fig. 82. Onchus Deweyii. Niagara Group. Lock- 
 port, New York. This is the earliest well-defined form of 
 a defensive fin bone of a fish, though fragments have been 
 seen in the Clinton Group. 
 
 Fig. 83. Osteolepis. A restored figure from Agassiz's 
 "Poissons Fossiles." Professor Agassiz says that some 
 
LIST OF FOSSILS. 61 
 
 scales of fishes from Silurian strata seen by him are 
 more nearly like those of Osteolepis than of any known 
 genus. 
 
 FOSSILS OF THE DEVONIAN SYSTEM. 
 
 Fig. 84. Lepidodendron. [ ? ] Ckemung Group. Che- 
 mung county, New York. 
 
 Fig. 85. Heliophyllum. Hamilton Group. Genesee 
 valley, shore of Lake Erie, at Eighteen Mile Creek. 
 
 Fig. 86. Lithostrotion. Corniferous Limestone. New 
 York. 
 
 Fig. 87. Cyathophyllum dianthus. Upper Helderberg 
 Limestones. Helderberg Mountains, and westward. 
 
 Fig. 88. Favositcs gothlandica. Upper Helderberg 
 Limestones. Helderberg Mountains, New York ; Ohio, 
 Kentucky, and Tennessee. 
 
 Fig. 89. Cyathocrinus [ ? ] ornatissimus. Portage 
 Group. Shore of Lake Erie, Chatauque county, New 
 York. 
 
 Figs. 90 and 91. Portions of Crinoidal columns. Onon- 
 daga Limestone. Helderberg Mountains to the Niagara 
 River, at Black Rock ; Ohio, Indiana, Kentucky, &c. Col- 
 umns of this character are remarkably characteristic of the 
 Onondaga limestone. 
 
 Fig. 92. Nucleocrinus elegans. Hamilton Group. 
 Moscow, and other localities in the Genesee valley, New 
 York. 
 
 Fig. 93. Strophodonta demissa. Hamilton Group. 
 Genesee valley, shore of Lake Erie. 
 
 Fig. 94. Chonetes carinata. Hamilton Group. Sen- 
 eca and Cayuga Lake valleys, Genesee valley, shore of 
 Lake Erie, New York. 
 
 Fig. 95. Spirifer medialis. Hamilton Group. Gen- 
 esee valley, New York. 
 6 
 
62 INTRODUCTION. 
 
 Fig. 96. Spirifer mucronata. Hamilton Group. Mad- 
 ison county and westward to the shores of Lake Erie. 
 
 Fig. 97. Spirifer cultrijugatus. Upper Helderberg 
 Limestones. Western New York, Ohio, and Kentucky. 
 
 Fig. 98. Calceola sandalina. Devonian rocks of the 
 Eifel, Germany. Specimens from the Upper Helderberg 
 Limestones, in Kentucky and Tennessee. 
 
 Fig. 99. Atrypa elongata. Oriskany Sandstone. Hel- 
 derberg Mountains, Schoharie, &c., New York. 
 
 Fig. 100. Atrypa aspera. Hamilton Group. Gene- 
 see valley, shore of Lake Erie, New York. 
 
 Fig. 101. Atrypa coiicentrica. Hamilton Group. 
 Seneca and Cayuga Lake shores, Genesee valley, shore of 
 Lake Erie, New York. 
 
 Fig. 102. Avicula flabella. Hamilton Group. Mad- 
 ison county, New York. 
 
 Fig. 103. Avicula longispina. Ckemung Group. 
 Steuben county. 
 
 Fig. 104. Cypricardia [ ? ] rhomboidea. Hamilton 
 Group. Cayuga and Seneca Lake valleys, New York. 
 
 Fig. 105. Grammysia Hamiltoneusis. Hamilton 
 Group. Madison county, valleys of Cayuga and Seneca 
 Lakes, New York. 
 
 Fig. 106. Ix>xonema nexilis. Hamilton Group. Mad- 
 ison county, valleys of Cayuga and Seneca Lakes, New 
 York. 
 
 Fig. 107. Pleurotomaria sulcomarginata. Hamilton 
 Group. Madison county, New York. 
 
 Fig. 108. Acroculia dumosa. Corniferous Limestone. 
 Helderberg Mountains, New York; Ohio, Indiana, Ken- 
 tucky, and Tennessee. 
 
 Fig. 109. Goniatites. Marcellus Shale. Schoharie 
 and Manlius, New York. 
 
 Fig. 110. Phacops selennrus. Corniferous limestone. 
 Helderberg Mountains, Schoharie, Cazenovia, New York. 
 
f VMfVFF:-?.- 
 
 LIS OP FOSSILS. 63 
 
 Fig. 111. Phacops (Cryphaas] calliteles. Hamilton 
 Group. Valleys of Cayuga and Seneca Lakes, Genesee 
 valley, shore of Lake Erie, New York. 
 
 Fig. 112. Homalonotus Dekayii. Hamilton Group. 
 Cazenovia, and other localities in Madison county, New- 
 York. 
 
 Fig. 113. Phacops bufo. Hamilton Group. Madi- 
 son county, valleys of Cayuga and Seneca Lakes, Geneseo 
 valley, shore of Lake Erie, New York ; Canada West, 
 Ohio, and other western localities. 
 
 Fig. 114. Cephalaspis Lyellii. Old Red Sandstone, 
 Scotland. 
 
 Fig. 115. Ptericthys cornutus. Old Red Sandstone, 
 Scotland. 
 
 Fig. 116. Scales of Ptericthys cornutus. 
 
 Fig. 117. Holoptychius nobilissimus, a single scale 
 Red Sandstone of the Catskill Mountain Group. Bloss- 
 burg, Pennsylvania. This species occurs, with the two 
 preceding species, in the Old Red Sandstone of Scotland. 
 
 Fig. 118. Byssacanthus crenulatus. The bony ray 
 or dorsal spine. (Ichthyodorulite.) Old Red Sandstone. 
 Russia. 
 
 Fig. 119. Dendrodus latus, a tooth. Old Red Sand- 
 stone. Scotland. 
 
 Fig. 120. Coccosteus decipiens. Teeth of this spe- 
 cies. Old Red Sandstone. Scotland. 
 
 Fig. 121. Dendrodus sigmoidalis, a tooth. Old Red 
 Sandstone. Scotland. Teeth of a species of Dendrodus 
 and of Coccosteus are associated with the scales of Holop- 
 tychius, (fig. 117,) in the Red Sandstone of Blossburg, 
 Pennsylvania. 
 
 Fig. 122. Diplocanthus striatus, a spine. Old Red 
 Sandstone. Scotland. 
 
 Fig. 123. Dipterus. A restored form from the frag- 
 ments occurring in the Old Red Sandstone of Scotland. 
 
64 INTRODUCTION. 
 
 FOSSILS OF THE CARBONIFEROUS SYSTEM. 
 
 Fig. 124. Sphenophyllum erosum. Coal Shale of 
 Carboniferous formation. 
 
 Fig. 125. Asterophyllites equisetiformis. Coal Shale. 
 
 Fig. 126. Pecopteris Sillimanii. Coal Shale. Penn- 
 sylvania and Ohio. 
 
 Fig. 127. Pecopteris. Coal Shale. Pennsylvania and 
 Ohio. 
 
 Fig. 128. Neuropteris. Coal Shale. Pennsylvania 
 and Ohio. 
 
 Fig. 129. Sphenopteris elegans. Coal Formation. 
 Europe. 
 
 Fig. 130. Stigmaria ficoides. Coal Formation. Eu- 
 rope and America. 
 
 Fig. 131. Sigillaria. A part of the stem and roots, as 
 it stands in a coal mine near Liverpool, England. 
 
 Fig. 132. Sigillaria. A portion of the surface en- 
 larged from the preceding figure, but still less than the nat- 
 ural size. 
 
 Fig. 133. Calamites approximata. Coal Shale. Eu- 
 rope and America. 
 
 Fig. 134. Archimedes. Carboniferous Limestone. In- 
 diana, Illinois, and Kentucky. 
 
 Fig. 135. Polypora. Carboniferous Limestone. St. 
 Louis, Missouri. 
 
 Fig. 136. A portion of the poriferous surface of the 
 preceding fossil enlarged. 
 
 Fig. 137. Pentremites florealis. Carboniferous Lime- 
 stone. Indiana, Kentucky, Tennessee, and Alabama. 
 
 Fig. 138. Pentremites pyriformis. Carboniferous 
 Limestone. Same localities as the preceding. 
 
 Fig. 139. Actinocrinus 30-dactylus. Carboniferous 
 Limestone of England. 
 
 Fig. 140. Terebratula hastata. Carboniferous Lime- 
 
LIST OF FOSSILS. 65 
 
 stone of England. A similar or identical species is known 
 in the Carboniferous limestone of Indiana. 
 
 Fig. 141. Spirifer attenuatus. Limestone, alternating 
 with Coal beds. Ohio, Indiana, and Kentucky. 
 
 Fig. 142. Spirifer. Yellow Sandstones, Mow the Car- 
 boniferous Limestones. Ohio, Indiana. 
 
 Fig. 143. Productus punctatns. Carboniferous Lime- 
 stone. Kentucky, Ohio. 
 
 Fig. 144. Productus semireticulatus. Carboniferous 
 Formation. Pennsylvania, Ohio, Indiana, Kentucky, Ala- 
 bama, and Missouri. 
 
 Fig. 145. Monotis. Yellow Sandstones, below the Car- 
 boniferous Limestone. Ohio and Indiana. 
 
 Fig. 146. Allorisma. Yellow Sandstones, below Car- 
 boniferous Limestone. Ohio, Indiana, and Kentucky. 
 
 Fig. 147. Macrocheilus. Coal Measures. Ohio. 
 
 Fig. 148. Euomphalus catillns. Carboniferous For- 
 mation. Europe. 
 
 Fig. 149. Bellerophon tenuifascia. Carboniferous 
 Limestone of Europe. 
 
 Fig. 150. Goniatites striatus. Coal Shale. Europe. 
 
 Fig. 151. Phillipsia globiceps. Carboniferous For- 
 mation of Ireland. 
 
 Fig. 152. Dithyrocaris Scouleri. Carboniferous rocks 
 of Ireland. 
 
 Fig. 153. Limulus trilobitoides. Coal Measures. 
 England. 
 
 Fig. 154. Cochlearus contortns. Coal Formation. 
 Europe. 
 
 Fig. 155. Scale of Megalichthys Hibbertii. Coal 
 Measures. Scotland. 
 
 Fig. 156. Tooth of Psammodus longidens. Carbon- 
 iferous. Europe. 
 
 Fig. 157. Megalicthys Hibbertii. A tooth. Coal 
 Measures. Scotland. 
 6* 
 
66 INTRODUCTION. 
 
 Figs. 158 and 159. Teeth of Diplodus gibbosus. 
 Coal Shale. England. 
 
 Fig. 160. Dorsal spine of Tristychius arcuatus. Coal 
 Measures. Scotland. 
 
 Fig. 161. Spine of Gyracanthus tuberculatus. Coal 
 Measures. England. 
 
 Fig. 162. Pygopterus. (Restored figure.) Carbonif- 
 erous. Europe. 
 
 Fig. 163. Amblypterus. (A restored figure.) Coal 
 Formation of Saarbruck. 
 
 SECONDARY FOSSILS. 
 
 FOSSILS OF THE PERMIAN, TRIASSIC, AND OOLITIC 
 SYSTEMS. 
 
 Fig. 164. Neuropteris liniuea- folia. Lias. Rich- 
 mond, Virginia. 
 
 Fig. 165. Zamites obtusifolius. Lias. Richmond, 
 Virginia. 
 
 Fig. 166. Cycadites megalophyllus. Oolitic. Eng- 
 land. 
 
 Fig. 167. Taeniopteris magnifolius* Lias. Rich- 
 mond, Virginia. 
 
 Fig. 168. Anthophyllum obconicum. Coral Rag. 
 Wiirtemburg, Germany. 
 
 Fig. 169. Astrea tubulosa. Coral Rag. Wiirtem- 
 burg, Germany. 
 
 Fig. 170. Caryophyllia annnlaris. Coral Rag. Eng- 
 land. 
 
 Fig. 171. Encrinites liliiformis. Muschdkalk. Near 
 Gottingen. 
 
LIST OF FOSSILS.' 67 
 
 *^ 
 
 Fig. 172. Apiocrinites rotundas. Oolite. Bradford, 
 England. 
 
 Fig. 173. Apiocrinites rotundus. (Restored figure.) 
 Oolite. Bradford, England. 
 
 Fig. 174. Cidaris coronata. Coral Rag. England. 
 
 Fig. 175. Terebratula digona. Oolite. England and 
 Germany. 
 
 Fig. 176. Trigonia costata. Oolite. England and 
 the continent of Europe. 
 
 Fig. 177. Gryphaea incurva. Lias. England and 
 the continent of Europe. 
 
 Fig. 178. Ammonites nodosus. Muschelkalk. Ger- 
 many. 
 
 Fig. 179. Ammonites falcifer. Oolite. England. 
 
 Fig. 180. Ammonites jason. Oxford Clay. Eng- 
 land. 
 
 Fig. 181. Aspidorhynchus. (Restored figure.) Oolite. 
 Solenhofen, Bavaria. 
 
 Fig. 182. Placodus Andriani. Muschelkalk. Bam- 
 berg, Bavaria. 
 
 Fig. 183. Ichthyosaurus communis. Lias. Eng- 
 land. 
 
 Fig. 184. Plesiosaurus dolichodeirus. Lias. Eng- 
 land. 
 
 Fig. 185. Pterodactylus crassirostris. Oolite. So- 
 lenhofen, Bavaria. 
 
 Fig. 186. Megalosaurus Bucklandii. Oolite. Stones- 
 field, England. 
 
 Fig. 187. Mastodonsaurus * Jaegeri. Keuper. Wiir- 
 temburg. 
 
 v Fig. 188. Ornithicnites. (Tracks of birds.) Sand- 
 stone, age of Trias. Connecticut River valley. 
 
 Fig. 189. Phascolotherium Bucklandii. Oolite. 
 Stonesfield, England. 
 
 * Labyrinthodon of Owen. 
 
INTRODUCTION. 
 
 FOSSILS OF THE CRETACEOUS SYSTEM. 
 
 Fig. 190. Equisetum Lyellii. Wealden. England. 
 Fig. 191. Lonchopteris Mantellii. Wealden. Eng- 
 land. 
 
 Fig. 192. Anthophyllum Atlanticum. Green Sand. 
 New Jersey. 
 
 Fig. 193. Ventriculites. Chalk. Lewes, England. 
 Fig. 194. Coeloptychium agaricoides. Green Sand. 
 Westphalia. 
 
 Fig. 195. Hallirhoe costata. Chalk. Eno-knd 
 Fig. 196. Idmonea contortilis. Yellow Limestone, 
 Cretaceous formation. Timber Creek, New Jersey. 
 
 Fig. 197. Marsupites ornatus. Chalk. Lewes and 
 Brighton, England. 
 
 Fig. 198. Ananchytes ovatus. White Chalk. Eng- 
 land. 
 
 Fig. 199. Spatangus parastatus. Cretaceous forma- 
 tion. New Jersey. 
 
 Fig. 199 a, Galerites cretosus. (Base of specimen.) 
 Chalk. Lewes, England. 
 
 Fig. 200.* Cidarites armiger. Cretaceous formation. 
 New Jersey. 
 
 Fig. 201. Terebratula Sayii. Green Sand. New 
 Jersey. 
 
 Fig. 202. Terebratula Harlani. Cretaceous Lime- 
 stone. New Jersey. 
 
 Fig. 203. Gryphaea convexa. Green Sand. New 
 Jersey. 
 
 Fig. 204. Pecten quinquecostatus. Green Sand. 
 New Jersey. 
 
 Fig. 205. Plagiostoma spinosmn. Upper White 
 Chalk. England. 
 
 * In some copies of the chart marked 203. 
 
LIST OF FOSSILS. 69 
 
 Fig. 206. Inoceramns. Cretaceous formation. Near 
 the base of the Rocky Mountains. 
 
 Fig. 207. Ammonites Conradi. Cretaceous forma- 
 tion. Alabama. 
 
 Fig. 208. Scaphites Iranii. JVeocomien. Europe. 
 
 Fig. 209. Turrilites catenates. Chalk. France. 
 
 Fig. 210. Hamites attenuates. GauU. England and 
 continent of Europe. 
 
 Fig. 211. Baculites anceps. White Chalk. England. 
 
 Fig. 212. Belemnitella Americana. Green Sand. 
 New Jersey. 
 
 Fig. 212 *.f Claw of Astacus Sussexiensis. Chalk. 
 Lewes, England. 
 
 Fig. 213. Macropoma Mantellii. Cretaceous forma- 
 tion. Lewes, England. 
 
 Fig. 214. Coprolite of Macropoma Mantellii. 
 
 Fig. 215. Ptychodns spectabilis. A dorsal spine. 
 Chalk. Lewes, England. 
 
 Fig. 216. Palajorhyncum latem. Slates of Glaris, 
 Switzerland. 
 
 Fig. 217. Beryx microcephalns. Scales. Middle 
 Chalk. Lewes, England. 
 
 Fig. 218. Corax pristodontes. Chalk. Europe. 
 
 Fig. 219. Ptycodus Mortoni. Cretaceous formation. 
 Alabama. 
 
 Fig. 220. Otodus appendiculatus. Chalk. Europe 
 and America. 
 
 Fig. 221. Tooth of Iguanodon Mantellii, (young.) 
 Lower Green Sand. England. 
 
 Fig. 222. Teeth of Iguanodon Mantellii. An older 
 individual, and the tooth worn. 
 
 Fig. 223. Jaw and teeth of Mosasaurus Hoflmaiiii. 
 Upper Chalk formation. Maestricht. 
 
 t 212* In some copies of the chart, the asterisk is wanting after 
 the figures 212. 
 

 70 
 
 INTRODUCTION. 
 
 FOSSILS OF THE TERTIARY AND QUATERNARY 
 SYSTEMS. 
 
 Fig. 224. Mimosites Browniana. Tertiary. Suf- 
 folk, England. 
 
 Fig. 225. Pecopteris [?] undulata. Tertiary. Rocky 
 Mountains. 
 
 Fig. 226. Glossopteris [ ? ] [Fucoides.] Tertiary. 
 Rocky Mountains. 
 
 Fig. 227. Sphenopteris Fremontii. Tertian). Rocky 
 Mountains. 
 
 Fig. 228. Madrepora palmata. Tertiary. Chesa- 
 peake Bay. 
 
 Caryophyllia cespitosa. 
 
 Anthophyllum lineatum. Tertiary. Vir- 
 
 Fig. 229. 
 Fig. 230. 
 ginia. 
 Fig. 231. 
 Fig. 232. 
 Fig. 233. 
 Fig. 234. 
 Fig. 235. 
 
 Eocene 
 
 Spirolina stenostoma. Eocene 
 
 Oculina. Tertiary. Claiborne, Alabama. 
 Scutella Lyellii. Tertiary. Alabama. 
 Scutella Rogers!. Tertiary. Alabama. 
 Nummulites laevigatus. 
 Nummulites laevigatus. A section of the 
 same. Tertiary. England. 
 
 Fig. 236. Calcarina rarispina. 
 Paris Basin. 
 Fig. 237. 
 Paris Basin. 
 
 Fig. 238. Terebratula lacryma. 
 and Alabama. 
 
 Fig. 239. Plagiostoma dumosnm. Eocene Tertiary. 
 Carolina and Alabama. 
 
 Fig. 240. Ostrea panda. Eocene Tertiary. Alabama. 
 Fig. 241. Pecten Jeffersonius. Tertiary. Virginia. 
 Fig. 242. Pecten eboreus. Tertiary. North Caro- 
 lina and Virginia. 
 
 Tertiary. 
 Tertiary. 
 
 Tertiary. Carolina 
 
LIST OF FOSSILS. 71 
 
 Fig. 243. Cardita planicosta. Tertiary. Alabama. 
 
 Fig. 244. Area idonea. Tertiary. Alabama. 
 
 Fig. 245. Pectunculus subovatus. 
 
 Fig. 246. Crassatella alta. Tertiary. Alabama. 
 
 Fig. 247. Astarte undulata. Middle Tertiary. Vir- 
 ginia. 
 
 Fig. 248. Fusus contrarius. Red Crag. Norfolk, 
 England. 
 
 Fig. 249. Fusus qnadricostatus. Middle Tertiary. 
 Maryland. 
 
 Fig. 250. Cerithium giganteum. London Clay. 
 England. 
 
 Fig. 251. Turritella Mortoni. Eocene Tertiary. Fort 
 Washington, Maryland. 
 
 Fig. 252. Conus gyratus. Eocene Tertiary. South 
 Carolina. 
 
 Fig. 253. Nautilus ziczac. London Clay. Eng- 
 lanij. 
 
 Fig. 254. Cancer Leachii. (Sheppey Crab.) Lon- 
 don Clay. England. 
 
 Fig. 255. Sciaenurus. London Clay. Sheppey, Eng- 
 land. 
 
 Fig. 256. liOphius brachysomus. Tertiary. Europe. 
 
 Fig. 257. Smerdis minutns. Tertian/. Europe. 
 
 Fig. 258. Platax macropterygius. Tertiary. Europe. 
 
 Fig. 259. Spine of Spinax. Tertiary. Europe. 
 
 Fig. 260. Notidanus primigenius. Molasse. Swit- 
 zerland. 
 
 Fig. 261. Charcharodon angustidens. Tertiary. 
 South Carolina. 
 
 Fig. 262. Charcharodon megalodon. Tertiary. S. 
 Carolina. 
 
 Fig. 263. Andrias Scheuchzeri. Tertiary. Eu- 
 rope. 
 
 Fig. 264. Chelydra Murchisoni. Tertiary. Europe. 
 
72 INTRODUCTION. 
 
 Fig. 265.* Tooth of Basilosaurus (Zeuglodon] ce- 
 toides. Eocene Tertiary. Alabama. 
 
 Fig. 266. Palaeotherium magnum. Montmartre. 
 France. 
 
 Fig. 267. Palaeotherium gracile. Montmartre. 
 
 France. 
 
 Fig. 268. Molar tooth of Elephas primiaegenius. 
 Lacustrine deposits of Quaternary. Europe and America. 
 
 Fig. 269. Lower jaw of Dinotherium giganteum. 
 Tertiary. Europe. 
 
 Fig. 270. Megatherium Cuvieri. Quaternary. Pam- 
 pas of South America ; Georgia. 
 
 Fig. 271. Teeth of Megatherium Cuvieri. 
 
 Fig. 272. Skull of TJrsus spelaeus, (Cavern Bear.) 
 Modern or Quaternary Period. England and continent of 
 Europe. 
 
 Fig. 273. Skull of Castoroides Ohibensis. Lacus- 
 trine, deposits of Quaternary Period. New York and Ohio. 
 
 Fig. 274. Megaceras Hibernicum. Peat Mosses of 
 Ireland. 
 
 Fig. 275. Mastodon maximus. Lacustrine deposits of 
 Quaternary. All parts of the United States. 
 
 Fig. 276. Fossil Fly. (Family Tipulida.) Fresh 
 Water formation. Aix, Provence. 
 
 Fig. 277. Dinornis. Quaternary Period. New Zea- 
 land. 
 
 * This figure, on the left of 268, is, by mistake, numbered 271 
 on some copies of the chart. ' "A 
 
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