COTE.] PALEONTOLOGY MIOCENE PERIOD. 501 



M. 



Depth of ceutrum behind, Tvith hyapophysis 020 



Expanse of diapoi^hysis of fourth cervical 034 



Expense of zygapopiiyses of fourth cervical 033 



Length of ceutrum of first dorsal 025 



Width of centrum of first dorsal 020 



Depth of centrum of first dorsal , 014 



Width of humerus cist ally 024 



Length of radius 133 



Width, proximally 018 



Width distally, (greatest with ulna) 023 



Length of lunar, (anterior face) 009 



Length of magnum, (anterior face) 004 



Width of carpus distally 020 



Width of III. and IV. metacarpal proximally 019 



Width of III. metacarpal proximally Oil 



Width of III. metacarpal distally 009 



Length of III. metacarpal 131 



Length of proximal phalange 017 



Length of phalange of second row 010 



Total length of hind foot, (No. 2) 243 



Length of tarsus 040 



Length of astragulus 025 



Length of metatarsus 147 



Length of unguis 015 



HYPISODUS, Cope. 



Synopsis New Vertebrata Colorado, 1873, pp. 5, 7. — Bulletin U. S. Geological Survey, 



No. 1, p. 26. 



With this geuus we enter a group of true ruminants which are allied 

 in many respects to genera now living in the warm regions of Africa 

 and Asia, namely, the TragulidcB. The premolar teeth are similarly sec- 

 torial in their character, excepting the last in Hypisodus and Leptotne- 

 ryx, and the metapodial bones are co-ossified into a common bone late in 

 growth ; a deep intervening groove always remaining. The cuboid and 

 navicular tarsal bones are more or less completely co-ossified. The re- 

 lations of the lateral metapodial bones are not yet determinable. 



Dental formula of Hypisodus : I., |^ ; G., {; P. m., | ; M., |. In the 

 maxillary bone, two posterior premolars are preserved ; the last has a 

 single internal crescent, which extends from the posterior external cres- 

 cent as an oblique branch inward and forward. In the mandibular 

 series, the six incisors, two canines, and two first premolars form an 

 uninterrupted series of ten subequal teeth, and are followed by a long 

 diastema. There is no diastema behind the first premolar. The num- 

 ber and relations of the teeth (the P. m. superior nos.1-2 unknown) are 

 much as Poebrotherium, but the molars are more prismatic in form. 



Hypisodus minimus. Cope, Bull. U. S. Geol. Surv., 1874, No. 1, p. 26. 

 Leptanchenia minima^ Cope, Pal. Bull., No. 16, p. 8 ; Hypisodus cingens, 

 Cope, Synop. New Vert. Col., p. 7. 



Eepresented by numerous remains of a species not larger than a 

 gray squirrel. 



The antero-exterior vertical ridge of the molars is more prominent 

 and overlaps the preceding tooth more exteusively than in the other 

 species. The posterior-superior molar is narrowed behind, and has a 

 small heel-column. In the mandible, the third premolar is three-lobed, 

 and the first i)remolar is not separated from the second by a hiatus. 

 The superior molars exhibit no basal shoulder, but have distinct roots. 

 The inferior molars are still more prismatic, and the roots of the last 



