188 PROCEEDINGS OF THE ACADEMY OF 



In. Lin, 



Length centrum lumbar 1 9 



Width articular face 1 7-5 



Heiglit 1 6 



Length diapophysis 2 



Width neural canal "i , ■ f 3 



Whole height of I posterior I 3 g 



Length diapophysis of j lumbar. ^ ^ g.^ 



This is the type of genus, for in it the peculiar form of the diapophyses ex- 

 tends much further forward on the series of vertebraj than in any other. 



Priscodelphinus atropius Cope. 



This species is based upon three cervicals, and three dorsals of one, two 

 lumbars and one caudal of a second individual, one lumbar and one caudal of 

 another, and three lumbars of a fourth. The diapophysis of the caudal is 

 short and spine-like, as in the last genus, and the last lumbar has had a nearly 

 similar process. The centra of all' are veiy slightly depressed and constricted 

 medially. The dorsals are broadly rounded in section without inferior carina ; 

 on the last lumbar the latei'al face below becomes, as in other species, slightly 

 concave. 



This species differs from the P. bar Ian i in that the dorsal vertebras are 

 not so depressed, are stouter, and have not the median inferior keel seen in it. 



Id. Lin. 



Length of a dorsal (No. 1) 2 2 



Width articular face , 1 11-5 



Depth " " 1 7 



Height neural canal (No. 2) 9-7 



Length diapophysis (No. 1) 1 4 



Priscodelphinus harlani Leidy. 

 Proceed. Acad. 1851, 327. 



A few vertebrae of this species occur in the collection. 



Priscodelphinus conradi Cope. 



Delphinus conradi Leidy, Proc. Academy, 1853, 35, Cope, 1. c. 1867, 144. 



This appears to be an abundant species of our Miocene beds. We have tea 

 lumbars and one caudal vertebrae. Its affinities are apparently nearer the last- 

 mentioned species than any other, 



Priscodelphinus stenus Cope. 



This species is represented by two vertebrae, but quite characteristic ones 

 of the lumbar series. They indicate both the smallest and the most slender 

 species of the genus. A section of the vertebra would have an almost exact 

 pentagonal form, though the articular surfaces are subround, and, what occurs 

 in no other species, a little deeper than wide. The neural arch preserved is 

 elevated and possesses a weak pair of zygapophyses. The bases of the broken 

 diapophyses indicate that they are very wide. The lower face of the centrum 

 has a strong median longitudinal angle, stronger than in any species, and not 

 prolonged into a thin keel as in D. ha w ki n s i i. The planes of the centrum 

 are mostly straight. 



In. Lin. 



Length centrum ; 1 7-2 



Height 1 0-5 



Width 1 0-5. 



" neural canal 5-8 



" basis diapophysis 10 



Height neural canal 6 



" zygapophysis 8"2 



[July, 



