8 PROCEEDINGS OF THE ACADEMY OF 



Tretosphys GRAND.EV0S Cope. Delphinnpterns grandseviis Cope, Proc. A. N. 



S. 1868, 191. Friscodalpliinus grand»:vus Leidy, 1. c. 18, 51, 327. 



The caudals of Ibis dolphin were the parts of it first discovered. Since then 

 a lumbar of one, and a large part of the skeleton of another individual have 

 been received by the Academy, all being from the same locality, Shiloh, Cum- 

 berland Co., N. J. Unfortunately the last series contained no caudal verte- 

 bra? ; its reference to this species is not entirely established, though the cor- 

 rectness of the same is very probable. 



The remains of the most perfect individual consist of seven cervical, nine 

 dorsal, and seven lumbar vertebrse ; there are twenty-four ribs and the anterior 

 element of the sternum. The distinctive features of the vertebras have been 

 already given. The manubrium of the sternum is T-shaped, and is somewhat 

 expanded jjosteriorly. The anterior (inferior) face is plane, (slightly concave 

 antero-posteriorly) ; the margins rounded. The superior face is roof-shaped 

 to a median keel, which disappears posteriorly. 



Tketosphys gabbii, Delphinapterus gahbii Cope, 1. c. 191. 



No material characteristic of this species has been found since its descrip- 

 tion. 



Tretosphys ur.eus Cope, sp. nov. 



This species is established on a lumbar vertebra from the miocene- of Shiloh, 

 Cumberland Co., N. J., with which I have associated a caudal vertebra from 

 near the mouth of the Patuxent, which was lent me for determination by Philip 

 P. Tysun, State Geologist of Maryland. 



The character of elongation seen in the genus Zarhachis strikes the eye at 

 once in this species. Although not carried so far a? in tiiat genus, it exceeds 

 considerably species of this, or of Priscodelphinus, with which we are ac- 

 quainted ; hence, thongh the material is slight, there can be no doubt that it 

 represents an animal not previously known. 



The articular face of the lumbar is not complete in all its outlines, but has 

 evidently been as deep as wide, and perhaps nearly round. The median im- 

 pression is punctiform and remarkably strong. The profile of the inferior out- 

 line is concave and is constituted by an obtuse keel, on each side of which is 

 a short longitudinal depression. The diapophyses have been broken off, but 

 their bases are both broad and deep, slightly filling the concavity of the infero- 

 lateral face. Supero-lateral face strongly- concave in both directions. 



Lines. 



Length of centrum '. 39 



" " basis neurapophysis 28-5 



" " basis diapophysis 20 



Width neural canal 4 



The caudal has broad diapophyses and the band-like impression passing in 

 front of them, and converging the centre of the median line below, a character 

 seen in many species of the genus The points of attachments of chevron 

 bones are well marked ; they entirely disappear on the middle portion of the 

 centrum. The articular face is similar to that of the lumbar, but is a little 

 broader than high. The surfaces are everywhere concave, and are not marked 

 by any longitudinal ridges. 



The same vertebraj of T. g ra n d se v us present many ridges ; those of T. 

 lacertosus are variable. 



Lines. 



Total length 39 



Length basis neurapophysis 25 



" " diapophysis 24 



Width neural canal 2-6 



" articular face 25-5 



Depth articular face 21-3 



This is probably the second of the genus length, and the third in bulk. 



[March, 



