106 STUDIES OF TASMANIAN CETACEA, 



cation, incidental to lower muscular power. The post- 

 crbital processes of the frontals make such shallow curves, 

 anteriorly, that it is best to regard them as lines, and, as 

 such, they subtend angles of 60 degrees to the tops of the 

 arches, formed by the united surfaces of the maxillo- 

 frontal elements. On either side of the skull, the fron- 

 tals are seen to protrude beyond the maxillaries in this 

 region. The post-orbital processes approximate the 

 zygomatic pro'cessies of the squamosals to within a quarter of 

 an inch. Asi in all the Ddyhinida' of the normal type, the 

 malar bones have been disrupted, and are functionally 

 superseded by the powerful bony arches, composed of the 

 orbital moieties of the frontals, maxillaries, and inciden- 

 tally the zygomatic processes of the squamosals. The 

 malar bones are six inches long, measured in a straight 

 line from their aut-orbital junctions, with the super- 

 orbital plates of the maxillaries, to their terminations 

 at the zygO'matic processes of the squamosals. 



In male skulls^ — such as those under review — the pre- 

 maxillaries, when viewed in profile, give the following re- 

 sults. From the narial basin they arise with a well-marked 

 curve to the middle of the beak, next depress to form a 

 well marked hollow, elevate again, and, lastly, slowly 

 shelve off to the tip. In female skulls, the beak is much 

 more depressed, and unless one had noted these curves in 

 the male skull they would hardly be looked for. Having 

 once noted the well-marked profile of the male, the mo're 

 ea.sy curves of the female manifest themselves quite natur- 

 ally, although so slightly marked. 



The pterygoid bones are separated in male skulls by 

 the very small space of one-sixteenth of an inch. 



As in the skulls of Glohire'jiltahis, the pre-maxillary 

 and vomer appear in the palate. 



The broken and spongy alveoli (here and there 

 absorbed) suggest the following dental formula: — 

 24 . "24 



20 . 22 



In a general way anything up to 25 teeth may be 

 present, and even in old animals some of the posterior 

 teeth never function, as we have evidence to show. 



As we hold perfect skeletons of the two sexes of 

 the Tursiops, we propose to give comr>arative measure- 

 ments, this being, in our case, an exceptionally fine oppor- 

 tunity for such a, method of oresonting the facts, since both 

 animals were obtained in the flesh. Both animals were 

 fully matured, as their skeletons prove, the male was ten 



