226 DESCRIPTION OF VERTEBRATE REMAINS, CHIEFLY 



three and a half inches. The width between the outlets of the anterior branches 

 of the infra-orbital canals in the supra-orbital fossse is nearly six inches. 



In the broad deep hollow of the upper back part of the rostrum bounded by 

 the stout maxillary crests, the fossil bears a striking resemblance to the corre- 

 sponding part of Hyperoodon. In this, however, the intermaxillaries remain dis- 

 tinct in the median line, and neither of them exhibits the curious exostosis-like 

 development of the right prenarial fossa. Further, in Hyperoodon the high lateral 

 maxillary crests are crescentoid in an opposite direction — that is to say, they have 

 their convexity outward instead of inward. 



DIOPLODON. 



DiOPLODON PROROPS. 



Belemnoziphius prorops, Leidy: Proceedings Academy Natural Sciences, Philadelphia, 1876, 81. 



The beak of a Ziphioid Cetacean, represented in figures 3, 4, PI. xxx., from the 

 Ashley River phosphate beds, was presented to the Academy by Mr. C. S. Bement. 

 It indicates a fourth species of a genus, differing from the preceding; and pertained 

 to a smaller animal than any of the others. The specimen has the same ivory- 

 like density and is of a ferruginous brown hue. All the constituent bones are 

 co-ossified, as in the previous specimens, and in addition, the mesethm-oid cartilage 

 is ossified and fused with the surrounding bones, so that the beak is solid 

 throughout and exhibits no trace of a supra-vomerine canal, except perhaps at the 

 back part of the fossil. In the complete solidity of the rostrum it accords with 

 the character in this respect of the genus Dioplodon of Gervais, or the Belemno- 

 ziphius of Huxley. 



The specimen in its present condition, in the median line, is about eight inches in 

 length, and apparently less than an inch has been lost from the point. Viewed from 

 above, fig. 3, the outline forms an isosceles triangle with the sides curving inwardly, 

 but bulging a little near the apex. Viewed laterally, fig. 4, the upper outline from 

 the root forward appears convex with an irregular deflection from the middle to the 

 tip of the beak. Underneath, the line from the root forward presents a series of 

 three concavities successively diminishing in length and depth. The conjunctions 

 of the concavities form intermediate points, of which the posterior one is the more 

 prominent and occupies a central position of the rostrum. 



The upper part of the rostrum forms a median ridge from which the surface 

 slopes off to the lateral borders. The ridge is formed by the union of the inter- 

 maxillaries, but it exhibits no trace of their original separation. The back part 



