

592 C, SCHUCHERT PALEOGEOGRAPHY OF NORTH AMERICA 



Rliytophorus, and Goniobasis. As a rule, the fresh-water forms are found 

 in distinct beds associated with land molhisks and land vertebrates. The 

 vertebrate life is very varied, but is largely composed of fragmentary ma- 

 terial, in the main of turtles and dinosaurs. "When considered in its en- 

 tirety, the vertebrate fauna of these beds is remarkably similar to, though 

 distinctly more primitive than, that of the Laramie. Almost or quite all 

 of the Laramie types of vertebrates are present, though, as a rule, they are 

 represented by smaller and more primitive forms." 256 



Eastern and southern or Ripley faunas of Montana time. — Weller 257 has 

 recently redescribed the northern Eipleyian and Jerseyian faunas, con- 

 sisting of about 600 forms. He states that "a considerable number of 

 species have an extraterritorial distribution, and by far the larger number 

 of these species which occur outside of New Jersey are known from the 

 Upper Cretaceous formations of the Gulf -border region, in the Eipley and 

 associated formations of Alabama, Mississippi, Texas, etc." The relation- 

 ship with the Montana is also close, but less than that of the Gulf border. 



Along the Atlantic border the Eipley faunas are introduced by deposits 

 largely continental in character, which finally pass into marine beds. 

 These are the Earitan-Magothy formations, with a flora of about 150 spe- 

 cies. The marine faunas of these beds are small and rather of brackish- 

 water types. The Tuscaloosa and Tombigbee are also correlated with the 

 Magothy. 



In regard to the Eipley fauna, Stanton 258 presents the following sum- 

 mary : 



"Toward the south in New Mexico the littoral facies of the Montana fauna 

 blends with the Ripley fauna, which is well developed in the latest Cretaceous 

 formations of Texas, Mississippi, Alabama, and throughout the Atlantic coastal 

 plain to New Jersey. The Ripley and Montana faunas have many species in 

 common. ... In the Montana fauna the genus Inoceramus is very abun- 

 dant and varied, and ammonoids — especially Placenticeras, Baculites, Sca- 

 phites, and other evolute types — are abundant, while the Ostreidse, Venerida?, 

 Oardiidse, etc., and many types of gasteropoda, including Yolutida?, are greatly 

 developed. The Ripley fauna is more varied and luxuriant, so to speak, than 

 the Montana and apparently indicates a warmer, or at least a more favorable 

 climate. . . . The Montana fauna probably received some of its elements 

 directly from the Arctic, while the Ripley fauna came in from the Gulf of Mex- 

 ico and the Atlantic. With the connection between the Atlantic and Pacific 

 closed in the Mexican and Central American region as at present, the Gulf 

 stream would give similar conditions, and would distribute the Ripley fauna 





258 Stanton and Hatcher : Bull. no. 257, U. S. Geological Survey, 1905. 



257 Weller : Geological Survey of New Jersey, vol. 4. 1907. 



258 Stanton : Journal of Geology, vol. 17, 1909, p. 421. 



