Review of Recent Geological Literature. 135 
Zoology. By W. B. Scott and Henry F. Osborx. Although the first 
part of this paper was published in September, 1887, the contents of 
both parts may here be conveniently noticed, as the paper has been but 
recently concluded. As in other of their joint writings, the authors 
have divided their labor, the treatment of the Carnivora and Artlodac- 
tyla being by professor Scott and that of the Perissodactyla by professor 
Osborn. 
Part I, constituting No. 5 of vol. xin of the Bulletin of the Museum 
of Comparative Zoology at Harvard College, treats of White river Mio- 
cene mammals from Nebraska and Dakota. 
The skeleton of Ho plophoneus is very fully described and is illustrated 
with a restoration. Oreodon gracilis is found to possess a pollex, thus 
removing any suspicion that Prof. Scott's description of a pollex in 0. 
culbertsoni may have been based on a case of abnormal polydactylism. 
A skull and a hind foot, supposed to pertain to a single species, and 
referred to the European genus Hyothcrium, yield the first record of 
this genus from America and are described under the name Hyothc- 
rium (?) americanum. A study of the dentition and skeleton of Lepto- 
meryx leads the authors to consider this genus, with Schlosser, as a 
true traguline, as opposed to Ri'itimeyer's view that it is more nearly 
allied to the Camelidce. Illustrated comparative studies of the skulls of 
Menodus Colorado ensis, and the new species, M. twhoceras, M. dolichoce- 
ras, and M. platyceras, and a restoration of the skeleton of M. proutii 
are given. The genus Metamynodon is described as a successor of the 
middle and upper Eocene genus, Amynodon and of about double the 
size and strength of the latter, equalling in size the largest of modern 
rhinoceroses and representing a line distinct from that of Hyracodon, 
Aceratlierium, or Diceratherlum. Portions of the skeleton of Acera- 
therlum are described. The resemblance of Hyracodon to Hyrachyus 
and its analogies with the horse are mentioned, and two new species of 
the former genus, H. planiccps and H. Major are described. 
Part II of this paper, constituting vol. xx, No. 3, of the above men- 
tioned Bulletin, bears date of November, 1890, and is devoted especially 
to Loup Fork mammalia from Nebraska and Kansas. The following 
are the more important observations brought out in it : The discovery 
of the mandible of JElurodon hyamoides. The discovery of a femur 
closely like that of a lion, but indicating an animal larger than and 
distinct from Smilodon. The determination of the foot-structure of 
Merycochcerus (previously partly effected by Cope), which is found to be 
closely similar to that of Merychyus. A very complete description of 
the manus and pes of Elastomer yr, tin' genus being regarded, with 
Cope, as being in the ancestral line of the distinctively American deer. 
An account of the dentition and a description and restoration of the 
skeleton of Cosoryx, which is regarded as probably having its ancestry 
among John Day Miocene forms of Blastomeryx, and (with Cope) as 
itself ancestral to Antilocapra. Observations on the molars of the 
equine series. Observations on the manus and pes of Aoeratherlum. 
