840 



HISTORICAL GEOLOGY. 



The fossil plants of the Dunvegan group of northern Canada (north of 55° N.) con- 

 tain, according to Dawson, species of Magnolia, Lanrns, Ficns, Qtiercus, Fagiis, Betula, 

 Sequoia, and Cycads, and are referred to the age of the Niobrara. The plant-bearing Mill 

 Creek beds overlying the Lower Cretaceous of the Queen Charlotte Islands are made 

 Dakota in age ; and the Coal-measures of Vancouver Island are, on the same authority, 

 of the age of the Montana group. Dawson refers to this time Heer's Patoot flora of 

 Greenland. He compares this flora with that of Georgia, and from the general resemblance 

 in genera infers that the temperature of the region may have been, like that of Georgia, 

 about 65° F. The Laramie flora, he observes, is most remarkable for its Conifers, Taxites, 

 Sequoia, Thuia, etc., and for the great development of the genus Platamis; also for con- 

 taining some modern species of Ferns, as Onoclea sensibilis, Davallia tenuifolia. 



Eeferences to all papers and reports on fossil plants published before 1884 will be 

 found in Ward's Sketch of Palseobotany, U. S. G. S. Ann. Bep., vol. v. 



1379 



1377 



1378 



Animals. — Invertebrates. — The shells of Rhizopods, or Foraminifers, 

 are abundant in many of the beds in New Jersey, and still more so in those of 

 Texas. Sponges are thus far rare fossils in the beds. Corals are not numerous. 



One from the Ripley beds of Texas, 

 1377-1379. described and figured by C. A. White, 



is represented in Fig. 1377. No 

 coral reefs have been reported ; but 

 they may possibly exist underneath 

 the Tertiary of some part of the 

 Gulf or Atlantic border. Echinoids 

 occur of the genera Cidaris, Salenia, 

 Cassiduhis, Holaster, Hemiaster, and 

 others. Less than 35 Upper Creta- 

 ceous species are known from all 

 North America, while Great Britain 

 has afforded nearly 150. 



Brachiopods are few in species. 

 The two here figured, Terebratella 

 plicata (Fig. 1378), and Terebratida 

 Harlani (Fig. 1379) of Morton, are quite common in New Jersey. Meek 

 described only one Lingula, L. nitida, from the Upper Cretaceous of the 

 Continental Interior, and this was from the Fox Hills group. The contrast 

 in species between the closing period of the Mesozoic and that of the Paleo- 

 zoic is in no tribe more marked. 



Of the characteristic Lamellihranchs there are, in the Oyster family, the 

 genera Ostrea (Figs. 1380, 1381), Gryphcea (Figs. 1384, 1385), and Exogyra 

 (Fig. 1383) ; and in the Avicula family, Inoceramus, I. labiatus (Fig. 1386) 

 being very common. 



The Rudistes, one Neocomian species of which is figured on page 835 

 (Fig. 1361), are very rare fossils in America in the Upper Cretaceous. Fig. 

 1387 represents one species described by C. A. White from the Wallala 

 section of the Chico beds of California. " Other Gastropods of modern 

 forms are represented in Figs. 1388-1392. 



CoKAL. —Fig. 1377, Hindeastrsea discoid ea. Brachio- 

 pods. — Fig. 1378, Terebratella plicata ; 1379, Tere- 

 bratula Harlani. Fig. 1877, 0. A. White; 1378, 

 1379, Morton. 



