562 Reviewfi — Prof. W. B. Scott — Fossil Mammalia. 



" All the specimens indicate that the shells were of small size, 

 .... The most complete example has a length of 58 ram. ; the 

 apical cone measures 15 mm.; the entire diameter of the shell is 

 18 mm. at its widest part and 16 mm. at or near the aperture." 



The author regards this Cephalopodan type as most nearly related 

 to the genus Piloceras, but the figures accompanying the paper 

 so closely resemble those illustrating Dr. Gerhard Holm's paper, 

 "Ueber die Anfangskammer von Endoceras belemnitiforme" (Pal. 

 Abhandl., Dames and Kayser, vol. iii. (1), 1885, pi. i.), that it 

 would have been interesting if the author had pointed out the 

 characters by which his " new Cephalopodan type " differs generically 

 from Holm's Endoceras belemnitiforme. We think the two species 

 are certainly referable to the same genus, and if Holm's species 

 be a true Endoceras, Nanno becomes a synonym. It is, however, 

 interesting to find that a structure very similar to that described by 

 Holm has now been observed in American specimens. G. C Crick. 



11. — The Mammalia of the Deep-Kiver Beds. By W. B. Scott. 

 (Trans. Amer. Phil. Soc, Vol. XVII., pp. 55-185, Plates 1-6. 

 Philadelphia, 1894.) 



IN this paper the author describes in detail a collection of Mam- 

 malian remains from the Deep-River Beds of Montana, a series 

 of deposits occurring in a Tei"tiary lake basin, originally discovered 

 by Grinnell and Dall in 1875. The beds consist of an upper and 

 a lower division, from both of which collections have been made. 

 The upper division is considered to form the lowest horizon of the 

 Loup Fork Beds, which are referred by the author to the Upper 

 Miocene. The lower portion is regarded as being on the horizon 

 of the uppermost John Day. The former is tentatively correlated 

 with the Miocene of Steinheim and Sansan, the latter with that of 

 St. Gerand-le-Puy, while the White-Eiver Beds are considered to 

 be approximately equivalent to the deposits of Eonzon, and should 

 therefore be referred to the Oligocene. 



One of the most interesting forms from the lower division is 

 Cynodesmus thooides, a dog-like animal, represented in the collection 

 b}"^ a beautifully preserved skull, the upper portion of which is 

 broken away, exposing a natural cast of the brain case. The surface 

 of the cerebral hemispheres is much less convoluted than in any 

 recent member of the Canidge, and the cerebellum is only very 

 slightly overlapped by the hemispheres. The author considers that 

 this animal is probably on the direct line of descent of Canis, con- 

 necting the latter with Daphcenus of the "White-Eiver Beds, hence it 

 is possible that the Canidge must be added to the list of families that 

 originated in the New World. 



Of the Equida3, Desmathippus, a most important form connecting 

 Mioliippus with Protohippus, is fully described. The teeth are low- 

 crowned, with the valleys partly filled with cement, and, in the feet, 

 the lateral digits are fairly well developed. 



Of the genus Anchitherium (in the restricted sense employed by 

 the author, i.e. excluding Mioliippus and Mesohippus) , one species, 



