8 



ungulate with an unguiculate carpus and tarsus, the former is unguiculate with an- 

 ungulate (diplarthrous) carpus and tarsus. Thus the OhalicotheriidEe must be referred to 

 a distinct order of unguiculate Mammalia, whicn I have called the Ancylopoda, with the 

 above definition. Two genera belong to the single family, the Chalicotheriidfe, viz., 

 Chalicotherium Kaup, and Ancylotherium Graudry. Marsh has not yet shown how his 

 genus Moropus differs from Ancylotherium. The species described by Marsh under this 

 name are from the Loup Fork bed of Kansas. 



Although the species of Chalicotherium from the Cypress Hills is the first one 

 described from North American beds, it is not the first discovery of the genus. Professor 

 Scott showed me a series of superior molars from the Loup Fork formation of Kansas, from 

 the Agassiz Museum, which he identified as belonging to this genus. The present species 

 is of larger size than the Kansas form, and is apparently equal to the C. goldfussii of the 

 Upper Miocene of Europe. The occurrence of this form in the Oligocene or Lower 

 Miocene ("White River), as well as the Upper Miocene (Loup Fork), of this country, is a 

 noteworthy fact, but is parallel to its history in Europe. Described from the Upper 

 Miocene by Kaup, it was afterwards found in the Middle Miocene (C. grande) by Lartet, 

 and in the Upper Eocene (C. modicum) by Graudry. 



Chalicotherium bilobatum, Cope. 



American Naturalist, 1889, p. 151. 

 Founded on a mandibular symphysis and part of the left ramus of an adult animal, 

 which contains the alveoli of the anterior four molars and part of that of the fifth. All 

 the premolars are two-rooted, showing that they are but three in number. Canines and 

 incisors wanting, the anterior alveolar margin thin and prominent and bilobed, with a 

 median emargination. Symphysis coossified, with an angulate inferior margin, pos- 

 teriorly with a fossa on each side of the median line, sloping regularly upwards to the 

 alveolar margin, and concave above behind the margin. Minute traces of alveoli of a 

 canine and two incisors on each side, which were probably present in the fcetus. Length 

 of symphysis above, 120 mm. ; depth posteriorly, 48 mm. Length of symphysis in front 

 of p. m. iii. Length of premolar series, *75 mm. Length of m. i., 40 mm. 



DIPLARTHRA. 



PERISSODACTYLA. 



MENODUS, Pomel. 



This genus has received numerous accessions within the last few years through 

 the labors of Professors Scott, Osborn l and Marsh. To these may be added the species 

 obtained from the Cypress Hills area of the "White River series. As remarked by 

 Professors Scott and Osborn, the species of Menodus present parallel relations to those of 

 Symborodon, which latter may be regarded as descendants of the former, of more special- 



1 Preliminary Account of the Fossil Mammals from the White River Formation in the Mus. Comp. Zoology, 

 Bull, of the Mus., Vol. xiii., No. 5, 1SS7 ; Amer. Jour. Sci. and Arts, 1887, p. 323 ; Cope, Amer. Naturalist, 1887, 

 p. 926. 



