October 24, 1902.] 



SCIENCE. 



673 



eggs are unknown, but it seems probable that 

 we now know the principal types of eggs. 



Harrison G. Dyar. 

 U. S. National Museum, 

 October 1, 1902. 



RECENT ZOOPALEONTOLOGY. 



NEW VERTEBRATES OF THE MID-CRETACEOUS. 



The report just published on ' Vertebrata 

 from the Mid-Cretaceous rocks of the North- 

 west Territory of Canada ' * by Henry F. 

 Osborn and Lawrence M. Lanibe, forms the 

 second part of a ' series of descriptive and 

 illustrated quarto memoirs ' begun in 1891. 

 The first part, by the late Professor E. D. 

 Cope, is on ' The Species from the Oligocene 

 or Lower Miocene Beds of the Cypress Hills.' 



The determination by the Canadian Survey 

 of a Mid-Cretaceous and fresh-water fauna, 

 including fishes, batrachians, reptiles and 

 mammals, is a forward step of great impor- 

 tance in vertebrate paleontology. The Survey 

 had established beyond question, geologically, 

 that the Belly River series is Mid-Cretaceous, 

 that it underlies the Montana or Ft. Pierre- 

 Fox Hills group, and overlies the Ft. Benton 

 and Dakota groups ; and at the outset of the 

 paleontological investigation for this report, 

 the question arose. What stages of vertebrate 

 evolution are represented by the Belly River 

 fauna? It soon appeared to Professor Os- 

 born in the study of the fine collection made by 

 Mr. Lambe that the Belly River vertebrates of 

 the Northwest Territory were of decidedly 

 different and apparently of older type than 

 those from the Laramie beds, of Converse 

 Co., Wyoming, described by Marsh, and were 

 rather to be compared with those described by 

 Leidy, Cope and Marsh, from Montana, 

 chiefly from the Judith River beds, which 



* ' Contributions to Canadifin Paleontology,' 

 Vol. III. (4to), Pt. II., 'Vertebrata of the Mid- 

 Cretaceous of the Northwest Territory.' ( 1 ) 

 ' Distinctive Characters of the Mid-Cretaceous 

 Fauna,' by Henry Fairfield Osborn, Vertebrate 

 Paleontologist (Honorary) of the Survey; (2) 

 ' New Genera and Species from the Belly River 

 Series (Mid-Cretaceous),' by Lawrence M. Lambe, 

 Assistant Paleontologist. Ottawa, September, 

 1902. 



overlie the Ft. Pierre in a region by no means 

 distant geographically. 



The Belly River or Mid-Cretaceous fauna 

 is distinguished from that of the Upper 

 Jurassic (Como Beds, Purbeekien) by the en- 

 tire absence of Sauropoda and by the presence 

 of Ceratopsia in great variety. It is affiliated 

 with that of the Jurassic, and, so far as we 

 know, separated from that of the Laramie by 

 the presence of highly specialized Stegosauria 

 or plated dinosaurs,* by numerous turtles of 

 the Jurassic family Pleurosternidas, and by 

 numerous large Plesiosaurs. There is very 

 little in common between the Belly River 

 fauna and the Laramie fauna of Wyoming 

 and Colorado so far as described, except the 

 dinosaur OrnitJwmimus and the very per- 

 sistent chelonian Baena. Most of the dino- 

 saurs will probably be found to be separated 

 generically. 



A comparison between all the Belly River and 

 Jiidith River or rather Montana and Laramie 

 (Colorado and Wyoming) vertebrates, so far 

 as named (111 species including many syn- 

 onyms), leads to the conclusion: (1) that the 

 Belly River fauna is more ancient in char- 

 acter both as to the older types of animals 

 which it contains and as to the stages of 

 evolution among animals which are also rep- 

 resented in the Laramie; (2) the geological 

 interval represented by the Ft. Pierre-Fos 

 Hills marine beds was accompanied by the 

 extinction of certain Jurassic types and pro- 

 gressive evolution of the persistent types; (3) 

 finally, the fossil land vertebrates hitherto de- 

 scribed from Montana probably are, in part 

 at least, of Mid-Cretaceous or Belly River age, 

 although the true Judith River beds certainly 

 overlie the Ft. Pierre and are of more recent 

 age. 



The descriptive section of the memoir by 

 Mr. Lambe is illustrated by twenty-one plates 

 and numerous text figures. The principal re- 

 sults are as follows : 



Numerous vertebra of a large plesiosaur 

 from the Belly River are provisionally re- 

 ferred to the New Jersey species Cimoliasaurus 



* The only published evidence of Stegosauria in 

 the Laramie of Wyoming and Colorado is the 

 tooth of Palwoscincus. 



