392 PROF. FLOWER ON A NEW [M**)' 2, 



and would be the means of obviating in future the confusion which 

 at present prevails for want of it." 



The following papers were read : — • 



1. On the Cranium of a new Species of Hyperoodon from the 

 Australian Seas. By William Henrv Flower^ LL.D., 

 F.R.S., P.Z.S., &c. 



[Eeceived April 18, 1882.] 



Dr. Gimther has been so good as to submit to my examination 

 the cranium of a Cetacean lately added to the British-Museum col- 

 lection which presents sufficient interest to justify its being brought 

 before the notice of this Society. The specimen was found upon the 

 sea-beach of Lewis Island in Dampier Archipelago, North-western 

 Australia. 



Unfortunately the cranium is in a greatly mutilated state, having 

 evidently been rolled for a considerable period among pebbles and 

 sand, from which cause many of its most important characters are 

 destroyed. The lower jaw is wanting. The whole of the elongated 

 narrow part of the rostrum is broken away. There is therefore 

 nothing remaining to indicate the character of the dentition. Many 

 prominent parts of the cranium, especially the supraorbital ridges, 

 are worn down to such an extent that their contour is completely 

 destroyed. This, as seen in figure 1 (p. 39.'{), is carried to a greater 

 extent upon the right than the left side. The slender jugal arclies 

 and the petrotympanic bones have disappeared. There is, however, 

 enough remaining to show that it does not belong to any known 

 species, and also to indicate, as far as they may be inferred from the 

 cranium alone, its affinities. It should be premised that the animal 

 to which it belonged was not very aged, as the sutures are mostly 

 open ; but there is no reason for supposing that it had not arrived at 

 its full size. 



It is evidently one of the Ziphioids ; and as the characters of the 

 four generic modifications of this group are plainly indicated in the 

 conformation of the upper surface of the cranium (see 'Transactions 

 of the Zoological Society,' vol. viii. p. 203), which is here well pre- 

 served, there is no difficulty in recognizing that it is neither a 

 Berardius, nor a Ziphius, nor a Mesoplodon, but that it comes so near 

 to Ilyperoodon that it is only with animals of that genus that it will 

 be necessary to compare it. 



An adult skull of the common specif, 77. rostratns, in the 

 British-]\Iusenm collection, which presents all the typical characters 

 of its kind, will serve very well for the purpose. 



Although the proportions differ somewhat, in general size the two 

 are nearly equal, the H.rostratus, on the whole, having the advantage. 



In the posterior or occipital aspect, the new cranium differs 

 from that of 77. rostralus in being narrower and somewhat higher. 



