

576 C. SCHUCHERT PALEOGEOGRAPHY OF XORTH AMERICA 



The higher Delaware formation introduces among other forms Fusili- 

 nella, Leptodus americanus (goes above), Richthofenia permiana (goes 

 above), Enteletes dumblei, E. angulatus, Strophalosia Jiystricula, Aulo- 

 steges mag nico status, MeeTcella skenoides, M. difficilis, Orthotetes nasuta 

 (large, of robusta type) ,Camaropkoria venusta, Hustedia bipartita, Bake- 

 wellia ?, Pteria (3), Myoconclia. Pleuropliorus, lYarthia americana, Waa- 

 genoceras cumminsi guadalupense, and the trilobite Anisopyge perannu- 

 lata (goes above). 



Besides those mentioned above, the Capitan has the following distinctive 

 forms: Geyerella americana, Leptodus guadalupensis, Stroplialosia cor- 

 nelliana (also in Brazil), Pugnax swallowiana, Dielasma prolongatum, 

 Dielasmina guadalupensis, Heterelasma (2), Spirifer mexicanus, S. sul- 

 cifer, Spiriferina (7), Composita emarginata, Hustedia meekana (also 

 below), Camptonectes ? (3), and Patella capitanensis. 



MESOZOIC ERA 



Triassic Period 

 See plates 86 and 87 



The widely emergent condition of the Permic persists into the Triassic, 

 and in all eastern Xorth America not a trace of marine deposits again 

 appears until well into the Cretacic. x\long the border region from South 

 Carolina to Kova Scotia, east of the Appalachians, in isolated structural 

 valleys, continental sediments accumulated, usually red in color, but at 

 the south with coal beds ranging in thickness up to 26 feet. These strata 

 are also known as the Xewark series, and are sometimes regarded as ex- 

 tending into the Jurassic, but the plants all seem to be of Triassic time. 

 In the northern areas there are many associated trap flows, both intrusive 

 and extrusive. 



Marine Triassic of the Pacific realm. — The emergent condition of east- 

 ern ^sTorth America throughout the Triassic is recorded all the way to the 

 Pacific by the absence of marine formations. The marine record is un- 

 usually complete in a restricted sea covering parts of California, Xevada, 

 Oregon, and Idaho, in sediments with considerable calcareous material 

 aggregating nearly 4,000 feet in depth. This series is rich in ammo- 

 nites. 220 The faunas are Pacific and Asiatic, with decided connections 

 with the great mediterranean Tethys. 



The lowest Triassic or Meekoceras fauna of California and Idaho 

 Smith 221 states to be a typical Pacific element, common also to the Hima- 



220 J. P. Smith : Professional Paper no. 40, U. S. Geological Survey, 1905. 



221 Smith : Festschrift v. Koenen, 1907. 



