AUT. 14. MARYLAND FOSSIL PORPOISE KELLOGG. 



Length lumbar (epiphyses hypothetical) 



Depth 



Width 



Width neural canal 



Length caudal (one epiphysis supplied) . 



Depth caudal 



Distance between inferior keels 



Width basis diapophysis 



In. 



Lin. 



6.5 



2.0 



3.0 



8.0 



10.5 



4.0 



10.5 



10.5 



A year later, Cope^ corrected his original description and gave a 

 synopsis of the characters of the species of this genus. It is evident 

 from the following quotation that the genus Zarhachis as amended 

 by Cope is not a natural assemblage. 



It was stated to differ from Priscodelphinus in that, while some caudals had 

 spinous diapophyses, others possessed them flat, but imperforate. A vertebra 

 supposed to indicate the latter characters I am now compelled to refer to an- 

 other species and probably genus*. Other vertebra assigned to C. flagellator 

 must be referred elsewhere. A lumbar vertebra represents another species of 

 probably the same genus, while a third has evidently pertained to still a third 

 species. The genus will be characterized by the extraordinary length and 

 slenderness of the lumbar vertebrae, and similar, though slightly abbreviated 

 form of the caudals. The latter have spinous diapophyses, and in one species 

 the former also. While the width of the articular faces of the centra of these 

 vertebrae in the typical PriscodeJ'phinus is but a few lines less the length, in the 

 species of this genus the diameter of the same is only from four-sevenths to 

 one-half of the length. The nearest approach is made by Priscodelphinus stenus, 

 where this diameter is six-sevenths of the length. 



I. Median or anterior caudal with strong longitudinal keel above the diapo- 

 physis — which is therefore probably present on the distal lumbars. 



Epiphysis thicker, larger Z. flagellator 



II. No longitudinal keel on lumbars, Diapophyses broad, flat ; epiphyses thin, 



large Z. tysonii. 



III. Diapophyses narrow, subspinous ; epiphyses thin, small. 



Z. velox. 



At this time the writer proposes to restrict the application of the 

 generic name Zarhachis to flagellator; the allocation of tysonii and 

 velox will be discussed in connection with other material which is 

 now being studied. So far as the present evidence goes, there are 

 some grounds for believing that caudal vertebrae like those of 

 Zarhachis flagellator can properly be associated with the present 

 specimen. 



The caudal vertebra in the Academy of Natural Sciences of Phila- 

 delphia which appears to be the type, and is so labeled, is much worn 

 at both ends, and the anterior epiphysis is missing. The lateral 

 processes and the neural spine are broken off ; the neural arch is com- 



»Cope, B. D., Proc. Acad. Nat. Sci.. Philadelphia, vol. 21. p. 9. 1869. 



