80 



THE VOYAGE OF H.M.S. CHALLENGER. 



Mr. J. W. Clark ' gives a careful description of the skins and the more salient features of 

 the skull of several specimens of the Grey Sea Lion from the Seal Eocks near Port 

 Stephens, New South Wales, which animal he identifies with the Otaria cinerea ofPeron. 

 The Anatomical Museum of the University, and the Museum of Science and Art, 

 Edinburgh, have recently purchased from Mr. Edward Gerrard, junior, skeletons of a 

 Seal from Victoria, belonging to this species, and the following description is drawn up 

 from the examination of the skulls of an adult male and female, and of a young animal, 

 the dimensions of which are given in the accompanying table : — 



Table X. — Skulls of Eumetopias cinereus. 



The occipital and sagittal crests are moderately developed in both the male and female, 

 but have not appeared in the young skull ; the sagittal crest scarcely reaches the con- 

 stricted part of frontal ; in the male a strong parietal tubercle like that seen in the adult 

 Otaria jubata is present. A marked character of the skull is its elongation in the adult 

 cranium in front of the cranial box, and this'is especially noticeable in the frontal con- 

 striction between the anterior wall of that box and the postorbital processes. At the 

 beginning of this constricted part the skull is pinched in laterally, and in front of this 

 constriction it widens somewhat before it reaches the postorbital processes. 2 The nasals 



1 Proc. Zool. Soc. Lond., March 18, 1884, p. 188. 



2 In comparing with each other the skulls of the Seals too much importance must not be attached to differences in 

 the length and degree of the constriction immediately in front of the cranial box as indicative of specific distinction. 

 In the comparison of the young and adult skulls of Macrorhinus leoninus and Otaria jubata in Part I. of this Report, 

 it is shown that this constriction is both much shorter and less marked in the young than in the adult skull of the 

 same species. In an interesting paper on Cranial Variation in Mvstela pennanti, Erxl. (Proc. Zool. Soc. Lond., Feb. 16, 

 1886), Mr. Oldfield Thomas has noted how much the interorbital constriction in this animal also is increased in the 

 aged skull. 



