1908.] NATURAL SCIENCES OF PHILADELPHIA. 27 



•The "different specimen" mentioned by Cope, and figured by Mr. 

 Case,® consists of two pairs of slender elongated bones, of which the 

 outer pair represents the superior rostral portion of the maxillee, and 

 the inner pair the superior rostral portion of the premaxillse. The 

 maxillae diverge at both anterior and posterior ends, while the pre- 

 maxillse diverge at the anterior end and convei'ge at the posterior end. 

 At the latter point, in the median hne, is inserted a piece of bone which 

 may represent a portion of the vomer or mesethmoid. 



After examining this specimen, I am of the opinion that it is not 

 properly put together, especially as a space is left between the maxillae- 

 and premaxillae proximally. The small fragment inserted between the 

 premaxillae does not belong in that position. It is unsymmetrical and 

 probably represents some portion of the maxilla. 



Traces of several alveoli are visible on the under side of the maxillae, 

 at the proximal end. That these bones are acuminate at this end is 

 due to the fact that both the inner and outer edges are abraded. The 

 bones should be turned outward somewhat on their axes, so that the 

 lower free border, which is now directed outward, would be directed 

 downward. This would bring the maxillae into such a position that 

 the upper surface would be horizontal proximally, very much as in 

 Inia. 



The two inner bones are probably premaxillae, although at the 

 anterior end the inner surface is plane or. slightly convex rather than 

 concave. At the middle, the inner wall is concave, with traces of a 

 continuous longitudinal ridge. If they are really premaxillae, they 

 should be transposed, that on the right side being placed on the left 

 and vice versa. At the same time they should be given a quarter 

 turn on their axes, so as to make horizontal the inner surfaces which 

 are now vertical. This would also cause the bones to diverge at the 

 posterior end, as they do in /ma and most other Odontoceti, leaving 

 space for the prenarial triangle. Their shape would then corre- 

 spond closely to that of the same bones in Inia, except that the 

 sides near the proximal end would be somew^hat more nearly vertical. 



The specimen probably represents a genus allied to Inia, but it is 

 impossible without more material to determine its relationships accu- 

 rately. It does not agree with any European genus of which the 

 rostrum has been figured, nor with any American genus of which the 

 rostrum is available for comparison. 



Rep. Maryland Geol. Surv., Miocene, PI. 15, fig. 



