:^0 Soitflicni Cyoss. 



Skulls. 



In tlie sjK'ciinens lirouj^lit Isoine by the 'Southern Cross ' the numbers 

 are th«»o usod l>y Mr. Hiinson. Of these four, one (No. 1) is the 

 snmlh'staihilt, another (N<». 2) the largest known, the latter exceeding 

 .sli"htlv in size No. Hl»7 of the ' Belfjica ' collection, which considerably 

 excecils thi' largest of Koss's own specimens (No. 43, 11, 25, 4). 



Jfustiin/uishiiiff characteristics. — The skull of Koss's Seal cannot 

 iHJSsibly be oonft»unded with that of any other living Pinniped. As 

 re«^»rds general a]>pearance, its nearest resemblances lie with Cysto- 

 nhora cri.stata, Er.xleben, of Arctic waters. In size it about equals 

 that of Lrptonychotis, and is slightly smaller than that of Lohodoa. 

 Here tlu' resemblance ceases: the feeble dentition, l)road inter- 

 zvgoujatie and short naso-palatal regions, together with the vertical 

 inclination of the nares, at once mark its distinctness. 



The cranial characters of Ommatophoca are exceedingly puzzling. 

 "Were it not for the differences of dental formulae (Ommatophoca 

 jiossessing one more incisor on each side of the lower jaw than 

 Cyslophora), we should have very strong grounds for including it in 

 the Cystoplwriuae. Indeed, its resemblances to CyslophorcL are very 

 remarkable. As pointed out by Sir W. Turner, the two skulls 

 approach each other in the vertical inclination of the anterior nares, 

 in their relation to the infraorbital foramina, in the great width of 

 the orl»its and interzygomatic regions, and in the length of the 

 ascending portions of the premaxillae. These are so short as to 

 leave a definite part of the anterior nares bounded by the superior 

 maxillae. He might have added the feebleness of the post-canine 

 dentition. They differ, however (besides the dental formula), in 

 the greater length of the nasals of Ommatophoca, in which also the 

 sup<irior maxilhie articulate with their outer border as far as the tip, 

 and do not leave tlie anterior part of their border free. Further, the 

 palati! plates of the palatal bones are shorter in Ommatophoca — a 

 character eviilently connected with the resonant vocal powers of the 

 animal — the upper incisors are immensely more feeble, and the shape 

 of the crowns of the cheek-teeth is quite distinct. 



Mo.st of these characters are peculiar to Ommatophoca and are not 

 i nd in any other genus, but, in addition to its dental formula, 

 wiiirh allie.s it to the Straorhynchinae, it finds a connection with 

 ili.a family through Lohodun, in which genus I find to a lesser degree 

 a similar conformation of the pre-maxillae. 



An at;count of the teeth will be given below. They do not help 



