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strata and probably some hundreds of feet of freshwater strata, is re- 

 markable enough ; but that it should reappear in company with its old 

 companions, the rare Dlphyodus and Scapherpeton, not to mention the more 

 highly developed fauna yet to be discussed, is very striking. Had there 

 occurred at both levels only some pebbles of three peculiar forms or com- 

 positions, instead of the three genera, the conclusion would have been in- 

 evitable that there was some particular connection between the two for- 

 mations. 



Cliampsosaiirus, Crocodiles. — Coming next to the reptiles, it may first 

 be noted that species of Ghampsosaurus occur in the Judith River beds, 

 in the Lance Creek beds, in those of the Hell Creek region, and in the 

 Puerco. It is probable that the species vary from one formation to the 

 other. The same statement can probably be made regarding the croco- 

 diles. These genera, common to all three of the formations under discus- 

 sion, ruay be left out of consideration ; although it must not be overlooked 

 that none the less they aid in binding together the formations in which 

 they are found. As to the crocodiles, it may be mentioned that Williston 

 recognized, in teeth and scutes found in the Lance Creek beds, Leidy's 

 Crocodylus humiUs, originally described from the Judith River region. 

 From the Judith River beds of Alberta Lambe described Leidyosu-chus 

 canadensis. Mr. C. W. Gilmore will soon describe a second species of the 

 genus, collected last summer in the Lance Creek beds of Converse County, 

 Wyoming. 



Turtles. — As regards the turtles, certain genera have already been 

 mentioned as appearing not to pass the line between the Lance Creek for- 

 mation and the Puerco and Fort Union. My study of the fossil turtles in- 

 dicates that the species of these animals rarely pass from one epoch to 

 another. If they have ever done so they passed from the Judith River 

 into the Lance Creek epoch. There are five or six species of Judith River 

 turtles which are represented in the Lance Creek and Hell Creek beds by 

 turtles of identical or very closely related species. Most of these are 

 marked by such peculiar sculpture that they are easily recognized and 

 some of them likewise are represented by excellent materials. I shall take 

 the pains to give some details. 



Compsemys? obscnra Leidy was originally described from beds 

 probably belonging to the Lance Creek epoch and found at Long Lake. 

 N. Dakota. Not much of it is known, but the sculpture is distinctive. 



