400 The American Naturalist. [May, 



while the present form is a Cotylosaurian reptile. Although so similar 

 superficially, the carapaces of the two differ as follows. In Dissorho- 

 phus transverse expansions of the neural spines of the vertebra? support 

 the transverse dermal bands below, and the ribs are free, and only reach 

 the border of the carapace by their extremities. In Otoccelus the 

 neural spines are not expanded, and the dermal bands rest immediately 

 on the ribs.— E. D. Cope. 



The Extent of the Triassic Ocean.— In a short note contrib- 

 uted to the Paris Academy of Sciences on December 30, Prof. Iness 

 calls attention to the striking geographical results of the researches of 

 his Vienna colleagues on the marine Triassic fauna. While to English 

 geologists the Trias is the typical example of an unfossiliferous land 

 deposit, the work of Mojsisovics on the contemporaneous deposits of 

 the Alpine region has been the starting point for a series of discoveries 

 in many parts of the world. A rich marine Triassic fauna is now 

 known, extending from Spain to Japan and California, and from 

 Spitzbergen to New Zealand. Yet among the thousands of these fos- 

 sils gathered together in Vienna from all parts, there is not a single 

 marine fossil from the regions bordering the Atlantic or Indian 

 Oceans. The conclusion is obvious, thas the regions of these modern 

 oceans were not covered by sea in Triassic times. On the other hand, 

 all the districts bordering the Pacific and Mediterranean yield the 

 marine forms, as does a great stretch of land extending from the Med- 

 iteranean to the Pacific through Central Asia, and another extending 

 from the Pacific through Eastern Siberia to the Arctic Ocean. Thus 

 the Pacific Ocean was the main ocean in Triassic times, and stretched 

 out two arms across the continental region — the one called the Tethyan 

 ocean, of which the Mediterranean is the last remnant, the other, the 

 Arctic branch. This distribution of the Triassic seas strikingly agrees 

 with that of the structural features of modern coast lines indicated by 

 Neumayr : the oceans bordered by lands with marine Trias are the 

 oceans of the Pacific type, of which the coasts are determined by the 

 convex margins of earth folds ; while the oceans of Atlantic type, of 

 which the margins cut across the mountain folds, are those around 

 which the only fresh water Triassic strata are found. Thus is con- 

 firmed the opinion that the latter oceans are of comparatively recent 

 origin, and have been produced by a process of wholesale depression, 

 which has cut off the three great triangular upstanding masses (or 

 horsts) of Greenland, Africa and India, which form so striking a fea- 

 ture on the surface of our planet. (Nature, Jan., 1896.) 



The Ancient Beaches of Erie and Ontario.— In his correla- 

 tion of the moraines of western New York with the Eaised Beaches 

 (Crittenden and Sheridan) of Lake Erie, Mr. Leverett makes the fol- 

 lowing statement in regard to the Lake Outlets : 



