106 STUDIES OF TASMANIAN CE.TACEA, 



cation, incidental to lower mxisciilar power. Tlie post- 

 orbital processes of the frontal? make sucji 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 from- 

 tals are seen to piotiude beyond the maxillaries in. this 

 region. The post-orbital processes approximate the 

 zygomatic processiesi of the squamosals to within a quarter of 

 an inch. Asi in all the Delj^hinidce. 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 superseded by the powerful bony arches, composed of the 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 zygoimatic processes of the squamosals. The 

 malar bones are six inches long, measured in a straight 

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

 orbital plates of the maxillaries, to their terminations 

 at the zygoimatic 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 hollov;-, elevate again, and, lastly, slowly 

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

 more depressed, and tinless 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 mon'e 

 easy ciu-ves of the female manifest themselves quite natur- 

 ally, although so slightly marked. 



The pterygoid bonesi are separated in male skulls by 

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



As in the skulls of Glohicepliahis, 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 comTDarative measure- 

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

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

 animals were obtained in the flesh. Both animals were 

 fully matured as their skeletons prove, the male was ten 



