58 EDWARD A. WILSON. 



Whereas if the habits of the Otariidse are examined, we find that : — 



In Ardoccpliahts forsteri the young is suckled for 5 months, during which it completes a natal 



moult before it takes to water. 

 In Ardocephalus hookeri,t]ie young is suckled for 5 months, and a natal moult is completed before it 



enters the water. 

 In Gallorhinus vrsinus, the young one is suckled for 3 months, and during the first month undergoes 



a natal moult before entering the water. 



Now, in the case of Macrorhinus, we are told (Lydekker) that the young are left 

 lying on the beach for as much as 6 or 7 weeks before entering the water, a period 

 which is longer than in any other case concerning which evidence is forthcoming 

 among the Pliocidse, and a period which is far more suggestive of the habits of the 

 Otariidse. We are told, on the other hand, by Professor Scott (in the " Trans. N.Z. 

 Inst," Ixi., Nov., 1880) that the young are suckled only for three weeks, and that they 

 are born in a black woolly coat, which is shed in a week, the coat which succeeds 

 it being also black. These accounts ajjpear to disagree, for the young would surely 

 enter the water as soon as their mothers finally deserted them, but on this point 

 Professor Scott is silent. 



Furthermore, attention may be drawn to the period of gestation, which seems to 

 be appreciably longer in the case of the eared seals than in the earless. More observa- 

 tions on this point are wanted, and it may be objected that such as we have are insuffi- 

 cient to argue from, Imt so far as they go they tend to place Macrorhinus at the 

 Otarian end of the Phocidse rather than, as Professor Flower would have us to do, as 

 far as possible from them. 



Periods of Gestation. 



Phoca vitulina ... ... ... ... ... ... '.) months (Reeks). 



Phoca grmnlandica months (Allen). 



Halichmrus ijrypus ... ... ... ... ... 1) months. 



Leptonychotes iceddelU ... ... ... ... ... 10 months. 



Erignathus harhatus ... ... ... ... ... 10 to 11 months (Collett). 



Macrorlunus leoninus ... ... ... ... ... 11 months. 



CaUorhinus ursinus ... ... ... ... ... 11 months, 2o days. 



Arctocephalus forsteri ... ... ... ... ... 11 to 12 months. 



Arctocqjhalus hoolceri ... ... ... ... ... 12 months. 



With regard to the presence of an under fur in Macrorhinus, as noticed by Gray, 

 I have not been able to draw any definite conclusion. Having had no opportunity of 

 examining the new-born young, the hairs of young adult animals have been my only 

 material for investigation, and I have been unable to see anything approaching the 

 character of " under fur " in tliem. Should there Ije such a thing, it affords one more 

 point of similarity between Macrorhinus and Ommatophoca, as well as between 

 Macrorhinus and the Otariidce. 



The position of the external nares is a point which does not seem to be highly 

 specialised in Macrorhinus for a life in the water. They are by no means so high on 

 the nose, nor do they open upwards so much as in the more specialised Phocidas, for 



