OCR Text |
Show 1881.] PROF. W. H. FLOWER ON THE ELEPHANT SEAL. 159 therefore, in all probability, a comparatively recent form, it must one of the most distant instead of nearest in true relationship, and all its resemblances to the Cetacea must be purely analogical and adaptive to existence under similar external conditions. Apart from these speculations, the facts which have been brought forward will, I think, be sufficient to induce practical zoologists to revise their systematic classifications of the Pinnipeds, in which this genu3 is almost invariably placed either in the middle of the group or next to the Otariidae. I would suggest that it ought to be placed as far as possible from the latter, the whole of the other Seals and the Walrus coming between. After its most close ally, the Bladder-nose (Cystophora cristata), the Leopard Seals of the southern hemisphere ( Stenorhynchina?) come nearest to it. Generic and Specific Designation.-Since the dismemberment of the Linnean genus Phoca by Nilsson in 1820, the Elephant Seal has been placed by various authors either in the genus Cystophora (Nils-son, 1820), Macrorhinds (F. Cuv. 1824), or Mirounga (Gray, 1827), modified by its author in 1847 to Moninga. The latter, founded upon a native Australian name mentioned by Peron, is clearly inadmissible, being exactly synonymous with Macrorhinus, which antedates it by three years, and which is now very generally used by the best authorities1. The question between Cystophora and Macrorhinus depends upon the varying estimate of the value to be assigned to a generic distinction. If the Bladdernose and the Elephant Seal are held to be sufficiently distinct in their organization to require separate generic appellations, the one will be called Cystophora and the other Macrorhinus. If otherwise, they will be both included under Cystophora, the older and equalhy appropriate designation. The differences between them have been carefully pointed out in Allen's recent monograph, and chiefly consist in the comparatively larger size of the crowns of the molar teeth, the frequent doubling of the root of the posterior, and occasionally of the penultimate, upper molar in the smaller species, combined with the greater prolongation of the palate backwards, the presence of claws upon the hind limbs, the less emar-gination of the distal border of the hind feet, the greater size of the pelvis and posterior extremities generally (which, according to Allen, are very feebly developed in the Elephant Seal), and the different form of the nasal appendage of the adult males. Differences of the auditory ossicles have also been pointed out by Mr. Doran. In all these characters, it will be observed, the Elephant Seal has undergone a further stage of specialization than the Bladdernose. It is a case in which, if they had never been separated, I, for one, should have been inclined to allow them to remain in the i It should be mentioned that F. Cuvier, as was his custom, only used the French form " Macrorhine" in the article in the Mem. du Mus. 1824, xi. p. 200. which gives some countenance to the citation of his first use of the genus Macrorhinus (as in Agassiz, ' Nomenclator Zoologicus') in the ' Dictionnaire des Sciences Naturelles,' xxxix. 1826, art. Phoque, and therefore to the priority of Latreille's use of the same name in the Fam. Nat. du Eegne Animal, 1825, for a genus of Coleoptera. |