246 EUMETOPIAS STELLERI STELLER's SEA LION. 



of these two species at my command are in the one case those 

 of very young animals, and in the other of very old males. A 

 fine series of the skulls of each enables me, however, to speak 

 witli confidence in respect to the matter of comparative size. 

 The largest old male skull of Eumetopias stelleri has a length of 

 400 mm., while none fall below 375 mm., the average being about 

 390 mm. In Otaria jubata, the largest old male skull in a series 

 of a dozen barely reaches 372 mm., and several fall below 340 mm.; 

 the average being about 355 mm., or about 50 rum. shorter than 

 the average of a similar series of Eumetopias stelleri. Adult 

 female skulls of the last-named species reach 290 to 300 mm., 

 while old female skulls of Otaria jubata about 265 mm. Accord- 

 ingly it seems fair to conclude that the linear measurements of 

 Otaria jubata are about one-eighth less than those of Eumetopias 

 stelleri, with a corresponding difference in the bulk and weight of 

 the entire animal in the two species. As very few measure- 

 ments of the skulls of Otaria jubata have been as yet published, 

 I append the following for comparison with those of Eumeto- 

 pias stelleri already given (antea, p. 238). The wide differences in 

 dentition and cranial structure have already been sufficiently 

 indicated. 



itself being loose and flabby. When the animal is at rest on a rock with its 

 hind flippers folded under its body, its head erect and the shoulders thrown 

 back, the loose skin and fat lies in folds, looking like the mane of a Lion ; 

 hence its name Sea Lion. This thickening of the neck is peculiar to the 

 adult male." MSS. notes. 



