778 APPENDIX. 



— 232, 233. Kinds and distribution of rocks. — 234. Important minerals. — Mode of oc- 

 currence of the gypsum, and its origin. — Mode of occurrence of salt. — 235. Absence of 

 fossils. — Geography and origin of the salt in the beds. — 236. Third Period of the Upper 

 Silurian. — Kinds and distribution of rocks, contrasting the Interior and Appalachian 

 regions. — 237. Rocks in the Connecticut valley. — 238. Abundance of life. — Promi- 

 nent kinds of animal life. — 240. Geography; contrast with the Salina Period. 



XVIII. Upper Silurian. — Page 241. Fourth Period of the Upper Silurian. — Kinds 

 of rocks and their distribution. — 242. Plants. — 242, 243. Common animal fossils. — 

 243, 244. Geographical facts connected with the Oriskany Period. 



Page 244. Distribution of the foreign Upper Silurian formation. — 245. Plants. — 

 Invertebrates. — Vertebrates. — 249. General characteristics of the Upper Silurian era. 



— 250. The Eastern-border region. — 250, 251. Conditions of the North American Con- 

 tinent. — 252. New feature among plants. — General fact with regard to the animal life. 



— 253. Climate. 



XIX. Devonian Age. — Page 254. Origin of the name Devonian. — Transition be- 

 tween Silurian and Devonian. — The four Periods in the American Devonian. — Lower 

 and Upper Devonian; distinction in rocks. — First Period of the Devonian. — Three 

 Epochs. — Kinds of rocks of the first two Epochs. — 255. Rock of the third Epoch, and 

 its distribution. — 257. Plants; Protophytes. — 257,258. Kinds of terrestrial plants. — 

 259, 260. Characteristic animal life. — 261. The first of Vertebrates yet found in Ameri- 

 can rocks. — 261-263. The first of the grand divisions represented, and the character- 

 istics of the species. — 263. The second of the grand divisions mentioned, and their 

 characters. — 264. Characteristic of the tails of the ancient Ganoids. — Third division of 

 fishes mentioned. — 265. The ordinary fishes not represented in the Devonian. — Geog- 

 raphy. — 266. Second Period of the Devonian, and its epochs. — Kinds of rocks and 

 their distribution. — 267. Ripple-marks, joints. — 268. Economical importance of the 

 Black Shale. — Kinds of terrestrial plants. — 269. Lepidodendrids; Sigillarids. — 270. 

 Ferns. — Kinds of Equiseta. — Kinds of Gymnosperms. — 271, 272. Predominant fos- 

 sils. — 273. Kinds of Articulates. — 274. Fishes. — 275. Geography. — 276. Life. 



XX. Devonian Age, concluded: — Page 276. Third Period of the Devonian. — The 

 two Epochs.— Kinds and distribution of rocks. — 277. Life. — 278, 279. Geographical, 

 conclusions. — 279. Fourth Period of the Devonian. — 279, 280. Kinds and distribution 

 of rocks. — 281. Geographical conclusions. — 282. Foreign Devonian ; what called in 

 Great Britain. — 283. Plants. — Animals: Coral reefs. — 284. Vertebrates; Placoderms. 



— 286, 287. General Geographical features of America. — 287. Condition of the region 

 of the Rocky Mountains and Appalachians. — Condition as to rivers. — 287, 288. Geo- 

 graphical changes. — Difference in rocks between the Appalachian and Interior regions. 



— Geographical condition of Europe. — 288. Great steps of progress in the life of the 

 world. — 288, 289. Changes in the life of the world during the Devonian Age. — 289, 

 290. Disturbances closing the Devonian Age. 



XXI. Carboniferous Age. — Page 291. The three Periods ; succession of phases. 



— 291, 293. Principal areas in North America. — 293. First Period. — Contrast between 

 the Interior and Appalachian regions in rocks. — 296. Plants. — 297. Prominent 

 features of the animal life. — 300. Trilobites; Insects. — 301. Classes of Vertebrates 

 represented. — 301, 302. The first American Reptiles; the division of Reptiles to which 

 it belonged, and the conditions under which the tracks were formed. — 304, 305. Geog- 

 raphy of North America. — 306. Resemblance of American and Foreign Subcarbon- 

 iferous. — 308, 309. Disturbances preceding the Carboniferous Period. — 309. Second 

 Period; the Coal areas of North America. — 310, 311. Kinds of rocks. — 312. Pro- 

 portion between the thickness of the Coal-measures and that of the Coal-beds. — 

 Evidence that beds are true Carboniferous. — Under-clays ; trunks of trees. — 314, 315. 

 Kinds of Coal. — 317. Vegetable remains in Coal. — 318. Iron-ore beds. — 321, 323. 

 Kinds of plants, and the groups to which they belong. — Relation in size to modern 

 Cryptogamous vegetation. — 324. Lepidodendrids. — 325. Sigillarids. — 326. Ferns. 



— 327. Calamites. — 329. Conifers. —331, 332 General character of the animal life. 



— 336. Kinds of Vertebrates represented. — Fishes. — 336, 340. Kinds of Reptiles. — 



