24 Dr. J. E. Gray on the Skulls 



Navomorpha lineatum. 



CaUidium lineatum, Fab. Syst. Ent. i. p. 189. 



Coptontma lineatum, White, Voy. Ereb. & Terr., Ins. p. 20, t. 4. f. o. 



Navomorpha sulcatum. 



CaUidium sulcatum, Fab. Syst. Ent. i. p. 189, 

 Coptomma acidipeniie, White, /. c. t. 4. f. 2. 



I have examined Fabricius's ty]ie in the Banksian collection, 

 and fail to detect any differences between it and the acutipenne, 

 White. 



Auckland ; Christchiirch. 



[To be continued.] 



V. — On the Skulls of Sea-hears and Sea-liotis (Otariadae), 

 and on the Seals of the Auckland Islands. By Dr. J. E. 

 Gray, F.K.S. &c. 



The British Museum contains a large series of the skulls of 

 Sea-lions and Sea-bears, I believe more numerous than those 

 of all other museums in Europe or North America put together ; 

 but the British-Museum collection, though large, does not afford 

 a complete series of the different ages of any one species. 

 Thus there are adult skulls of three species of Sea-lions, and 

 also a number of skulls of the young, but not of the inter- 

 mediate ages. It is the same with the different species of Sea- 

 bears ; there are skulls of adult and of very young of several 

 species. The most interesting series is that of the Antarctic 

 Hairy Sea-bear {Phocarctos Hookeri). 



The examination of the Museum series leads one, I think, 

 to the following conclusions : — 



The milk-teeth, like those of the Seals, are very small, and 

 are changed soon after birth, and are immediately followed by 

 the permanent series, in the following order : — 



The cutting-teeth are changed first, and after them the 

 grinders, which are followed by the canines, which do not 

 appear above the gums until after all the grinders are deve- 

 loped, and they continue to develop during the growth of the 

 young animal. The crowns of the second series of teeth are, 

 when they are first formed, of the size and form which they 

 retain during the life of the animal, and are only altered in 

 the adult age by the wearing away of the edge of the lobes of 

 the crown which are developed during youth. The roots are 

 being gradually developed during growth ; they are at first 



