REVIEWS. 



the eared seals proposed by this author in his above-cited paper. 

 While still agreeing with him in regard to the comparatively wide 

 separation of Zalophus from its nearest allies, and in regard to its 

 being intermediate between the fur and other hair seals in respect 

 to size, but only in this point, I am compelled to still differ with 

 him in respect to its constituting a primary group coordinate with 

 that of all the other eared seals. * Whilst a somewhat aberrant 

 form, it seems to me to be by no means very far removed from 

 Eumetopias and Otaria. ' I can, in fact, scarcely comprehend how 

 it has happened that the author in question has overlooked the 

 presence of a well developed sagittal crest in all the genera of 

 the Otariadce except Zalophus, as he seems to have done in the 

 differentiation of his two primary groups of this family. The 

 supposition that he has examined only the skulls of females or 

 young males of the other genera is hardly sufficient to explain this 

 oversight, since figures indicating its presence in the males of the 

 other genera have been long published, to say nothing of the many 

 distinct allusions to it by authors. While familiar with the distinc- 

 tive characters of Zalophus, he has failed to indicate them in his di- 

 agnoses, the comparatively unimportant character furnished by the 

 rostral outline being far less characteristic than its slender elon- 

 gated muzzle and other features, which had previously been well 

 pointed out by Dr. Gill, as well as by other writers. The sagittal 

 crest reaches, it is true, its maximum development in.Zaloplius; 

 but any one who has seen the high sagittal crest possessed by old 

 males of Eumetopias Stelleri, in which as a thin solid plate it at- 

 tains the height of 38 mm., or an inch and a half; and the rela- 

 tively scarcely less developed sagittal crest in old males of Callo- 

 rliinus ursinus ; and the figure of old male skulls of Otaria jubata, 

 and some of the species of Arctocephalus, in which a high sagittal 

 crest is represented ; cannot but be surprised to find in what is 

 assumed to be an enumeration of "the most obvious and dis- 

 tinctive characters" of the genera Callorhinus, Arctocephalm, 

 Otaria and Eumetopias, a diagnosis contrasting " a sagittal groove 

 from which are reflected the low ridges indicating the limits of the 

 temporal muscles" in these genera, with "a solid, thin, and much 

 elevated sagittal crest " in Zalophus ! The females of Callorhinus 

 ursinus and Otaria jubata, and, so far as at present known, of all 



*See American Naturalist, Vol. IV, p. 681. 



