308 PROCEEDINGS OP THE ACADEMY OF 



unique ; nothing like it is seen even in Perognathus ; its peculiarity 

 is on a par with the immense rostral development in a walrus for 

 example. The resulting figure, as one author has aptly remarked, 

 bears a ludicrously close resemblance to the buttocks of the squat- 

 ting human figure, the mastoids being the nates, the emargination 

 being the cleft between, and the foramen magnum having an ob- 

 vious suggestiveness. The whole surface of the skull is smooth, 

 and gently convex in all directions. There are no ridges or 

 roughnesses ; the sutures persist plainly visible in adult life ; and 

 all the bones are remarkably t^iin and papery. 



Viewed in profile, the skull shows notable features. The high- 

 est point is over the orbits, where the frontal and parietals are 

 seen to be swollen ; thence the superior outline sweeps gently 

 down to the occiput, and in the other direction proceeds in a nearly 

 straight if anything slightly concave line to the tip of the 

 snout. The great projection of the nasals beyond the intermax- 

 illaries is well shown. The incisors in profile are seen to curve 

 far backward as well as downward. The palatal outline is nearly 

 straight, and declivous from before backward. Behind the palate 

 a small pterygoid hook is seen ; but beyond this the whole outline 

 is the inflated portions of the temporal bone hiding eveiything 

 else. On the side of the rostrum midway, there is a large cir- 

 cular foramen, low down, but little above the palatal level ; this 

 is the orifice corresponding to the " anteorbital"* foramen, here 

 singularly displaced. From its fellow of the opposite side it is 

 only separated by a very thin vertical septum, apparently ethmoi- 

 dal. This delicate partition being often broken through in pre- 

 pared skulls, has occasioned the statement of the inter-communi 

 cation of the two foramina. But I find the septum complete and 

 intact in some specimens, and although a vacuity may very possi- 

 bly naturally occur, such does not appear to be the rule. The 

 orbits appear as a subcircular fossa, largely roofed over in front 

 by the thin expanded zygomatic plate of the maxillary, and 

 bounded below by the molar. Independent^ of its laminar max- 

 illary portion, the zygoma is a slender, straight thread down to 

 the palatal level, and abutting behind against the tympanic. The 

 actual suture is squamosal, as usual, but there is a curious appear- 

 ance of connection with one of the otic bones. In the general 

 inflation of the posterior portion of the skull appears the large 



