48 EDWARD A. WILSON. 



tion of the anterior nares, but in the relation of the anterior nares to the infra-orbital 

 foramen, in the width of the orbits and interzygomatic regions ; and in the small 

 proportion of the ascending parts of the premaxillse, which leave a large part 

 of the anterior nares to be bounded by the superior maxilla. To these I would add 

 that in Macrorhinus the premaxillse make no effort to reach the nasal bones at all 

 and leave the whole of the anterior nares to be bounded by the superior maxilla ; in this 

 respect very widely differing from the form of the same bones in the Stenorhinchinse. 



It is of course true, as Captain Barrett Hamilton has pointed out, that in some 

 respects the skulls of Ommatophoca and Cystophora differ. He allows, however, that the 

 few characters to which he draws attention do not bring Ommatophoca any nearer to 

 the Stenorhinchinse, and this is just the point I wish to urge. The resemblance of the 

 skull of Ommatophoca to that of Macrorhinus is seen to be very marked when only 

 immature skulls of the latter are taken for comparison, a point which it is well to bear 

 in mind when using such highly specialised animals for comparison as the adult Sea 

 Elephant. It is exactly as one would expect that Ommatophoca, in which no very 

 striking peculiarities have been developed, should find its closest resemblance in the 

 young and immature skulls of Macrorhinus, which represent far better than the 

 adults the more primitive type from which both of these seals as well as Cystophora 

 have probably sprung. There appears, moreover, to be some reason for believing that 

 Ommatophoca approaches Macrorhinus and Cystophora in the relative size of the sexes, 

 at any rate to a greater extent than do the other members of the Stenorhinchinse ; and 

 the evidence of all the fighting scars upon the adult males of Ommatophoca inflicted as 

 they are, solely on the head and neck, as in the Cystophorinse, and never on the body, 

 as in the Stenorhinchinse, affords strong support to the assumption that they fight 

 standing up to one another on their ,fore limbs, as do the Cystophorinse ; both Omma- 

 tophoca and the Cystophorinse approaching on this point far more closely to the 

 Otariidse than do any of the Stenorhinchinse. 



In food also, as one would expect from the form of the teeth, Ommatophoca agrees 

 with the Cystophorinse, both members of which are said to live mainly upon 

 cephalopods. There is also in the character of the hair of Ommatophoca a certain 

 similarity with that of Macrorhinus, both having short, flat, broad and decidedly 

 coarser hair than occurs in any of the Stenorhinchinse. 



There is, as I have said, a strong general similarity in the form of the hind 

 flippers of these two seals, a similarity which is not shared by other members of the 

 Stenorhinchince, and the extremely rudimentary nature of the claws upon the hind 

 limbs is characteristic of both, as also of Monachus, and different from those of 

 Stenorhinchus, Leptonychotes, and Lobodon, in all of which the claws are well developed. 



In the fore limbs, however, Ommatophoca stands apart with claws as rudimentary 

 as those upon its hind limb, whereas the claws of the fore limb in Macrorhinus and 

 Monachus and of both limbs in Cystophora and Ilalichcerus are exceptionally well 

 developed. 



