SEALS 7 



and is slightly smaller than that of Lobodon carcinophagus, but hère the resemblance ceases, and the 

 broad interzygomatic and short, thick naso-palatal régions, together with the vertical inclination 

 of the nares at once mark its distinctness. 



The resemblances of the skull to that of Cystophora and consequently on a small scale to 

 that of Macrorhinus were, I think, first described by Sir W. Turner, who remarked that the two 

 skulls approach each other in the vertical direction of the anterior nares, in the relation of the 

 latter to the infra-orbital foramina, in the great width of the orbits and interz} T gomatic région 

 and in the length of the ascending part of the premaxillae which are so short as to leave a 

 definite part of the anterior nares bounded by the maxillae. He might hâve added the feebleness 

 of the postcanine dentition. The skull of Ommatophoca differs, however, in the greater length of 

 the nasals and also in the fact that the maxillae articulate with the outer border of the nasals 

 and do not leave the anterior part of this border free. Further the palate plates of the palatal 

 bones are shorter in Ommatophoca than in Cystophora, a character evidently connected with the 

 résonant vocal powers of the animal, there is one more incisor on each side of the lower jaw, 

 the upper incisors are immensely more feeble, and the shape of the crowns of the grinders is 

 quite différent. 



A similar conformation of the premaxillae is found to a lesser degree in the skull of 

 Lobodon. 



The dentition of Ommatophoca is remarkably feeble. Thus with a skull attaining to more 

 than double the size of that of Phoca grocnlandica or P. vitulina, the teeth are about equal in size 

 to those of the former and actually less than those of the latter species. The only southern species 

 which at ail nearly approaches Ommatophoca in the size of the teeth is Lcptonychotes Weddclli ; 

 but hère again the canines of the latter species are many times larger than those of the former, 

 while the cheek-teeth also are larger and of a différent shape. In Ommatophoca thev are provided 

 with three cusps, the central of which is the longest and is recurved. In Lcptonychotes the rudi- 

 ments of posterior or anterior cusps even when présent are obscured by the prominence of the 

 central cusp. 



(b) Skeleton. — I regret that the time at my disposai has not permitted me to make a 

 minute examination of the skeleton. The numbers of vertebrae in the skeleton of the type 

 spécimen in the British Muséum are 7 in the cervical, 14 in the thoracic, 8 in the lumbar 

 and 4 in the sacral régions respectively. In most seals the numbers of thoracic and lumbar 

 vertebrae appears to be usually i5 and 3, more rarelv 14 and 6 (see Gadow's Edition of Flower's 

 Osteology of the Mammalia pp. 81-82, i885). 



(c) Of the external appearance of Ross' seal we knew practically nothing before the return 

 of the Belgian Antarctic Expédition. Gray's plate tells us little, and that naturalist stated that 

 the skin upon which the original description of the species was based was « greenish vellow, with 

 close oblique yellow (') stripes on the side, pale beneath ». Unfortunately no fresh skins hâve 

 reached this country with the présent collection, but an examination of the skin described by Gray 

 shows that the colours are as nearly as possible olive above gradually shading into tawny olive 

 beneath, with lighter yellowish régions on the breast and neck. There is no very distinct line of 

 démarcation between the colours of the upper and under surfaces. There are hardly any spots, 

 but the « stripes » of Gray are présent at the junction of the two colours and are represented on 



(1) Similar streaks are represented in Dr. Cook's photograph, reproduced as figure 10 of Monsieur Racovitza's 

 paper. 



