Dr. H. Burmeister on Globiocephalus Grayi. 53 



vomer, much shorter. The narrow form of the anterior part 

 of the intermaxillaries allows us to see a considerable portion 

 of the maxillaries on all sides of the tip of the nose ; these 

 appear only as a narrow band in the European species. The 

 form of the maxillaries, at their anterior extremity, is also 

 different ; they are here broader and shortly rounded, and 

 nearly parallel on the outer margins. The orbital part is not 

 so broad, and the hinder edge of the orbit not so prominent. 

 On the other hand, the cerebral region of the skull is broader, 

 and much more produced behind in my species. 



The small surface of the frontal bones seen behind the 

 maxillaries is comparatively broader, and the elevated margin 

 of the parietals which separates the upper surface of the skull 

 from the occipital surface is nearly in a sti-aight line, a little 

 undulated on each side, but by no means curved forwards as 

 in the European species. In the latter the exterior margins of 

 the occipital surface, which are also the hinder margins of the 

 temporal groove, are inclined backward on both sides ; but they 

 are perfectly parallel and much more prominent in G. Grayl, 

 so that the general form of the occipital surface in this species 

 is rather a plane than a portion of a spherical curve as in the 

 European species. Hence the occipital condyles are more pro- 

 minent posteriorly in the former and more retracted in the latter. 



Beneath, the general configuration of the skull is nearly the 

 same in both species ; but a very important difference is to be 

 found in the length of the teeth-series. In the European 

 species this series occupies only half the length of the margin 

 of the maxillary, but in the new Argentine species nearly the 

 whole margin, except only an extent of 2 inches at its hinder 

 extremity. This difference is very remarkable, and is due to 

 the greater size of the teeth, especially the anterior ones. The 

 European species has generally twelve teeth on each side, in 

 some cases fourteen, or, exceptionally, only eleven. My new 

 species has only nine teeth on each side in both jaws 5 and 

 these are of nearly equal size, except that the first is somewhat 

 smaller : in the European species, the first five teeth are very 

 small, increasing somewhat in size posteriorly ; and the seven 

 following ones also are not equal in size, but gradually m,- 

 creasing. All the teeth in G. Grayi are nearly of the same 

 form, having a truncated molar surface and a very short pro^ 

 minent crown ; more than two-thirds of each tooth is enclosed 

 in the alveolus, terminating below in a conical root which is 

 nearly closed, exhibiting only a very small opening h^ the 

 middle (PI. II. fig. 3, a tooth, half the natural size). 



The lower jaw is rather strong. Each ramus is 21 inches in 

 length, and 6 inches 4 lines in depth at the Avell-marked coro- 



