^ THE FUR SEALS OF THE PRIBILOF ISLANDS. 



Cuboid articulating with calcaneum only. First metatarsal articulating only with 

 entocuneiform. A trochanter minor present on femur. Auditorial bullas small and 

 irregular in form. 



PHOCOIDEA. 



Neck short. Hind feet incapable of being turned forward. Grinders with complex 

 roots and multicuspidate crowns. Mastoid swollen, but not salient. Tentorium 

 moderate or small. No alisphenoid canal. Auditorial bullae usually very large, 

 pyriform in shape. Posterior end of nasals wedged in between frontals. Anterior 

 digits all bearing claws, and claws present (usually) on all digits of hind feet. No 

 cartilaginous flaps to any of the digits. Astragalus equaling calcaneum in length. 

 Cuboid articulating with both calcaneum and astragalus (save in Monachus and 

 Macrorhinus). First metatarsal articulating with entocuneiform and with second 

 metatarsal as well. Femur with no trochanter minor. 



THE SPECIES OF CALLORHINUS OR NORTHERN FUR SEAL. 

 By David Starr .Jordan and George A. Clark.- 



The fur-seal herds resorting to the islands of Bering Sea and the Sea of Okhotsk 

 belong to the genus Gallorhinus; while those resorting to the islands of the Tropics 

 and the antarctic regions belong to a difi'erent group, called Arctocephalus. 



The fur seal of the North was first made known by Steller, who, in 1741, inspected 

 the South or Poludionnoye rookery of Bering Island, and wrote au account of his 

 observations. On Steller's description of the "Sea Bear" of Bering Island Linnaeus 

 based his classification of Phoca ursina, or "bear-like" seal. From the Linnaean 

 name the fur seal of the North came to be called Gallorhinus ursinus, and the type of 

 the species is, of course, the Commander Islands herd. 



The fact that the members of the Pribilof herd differ from those of the Com- 

 manders in color, in form, and in character of the fur has long been recognized. 

 These diflferences, thougli slight, are permanent and constant. No intermediate forms 

 are known, and, as the life courses of the herds are wholly distinct, apparently no 

 intermediate forms can exist. We may therefore hold the Pribilof herd to be a 

 species of fur seal distinct from that of the Commander Islands, This species may 

 be called Oallorhinus alascanus Jordan and Clark. 



The species alascanus may be known by the stouter, broader head, by the thicker 

 neck, by the prevalence of warm brown shades in the coloration of the female and 

 the young males, by the more silvery color of the gray pups, which lack the distinct 

 whitish patches on the rumps seen in ursinus, and, in general, by the lack of sharp 

 contrasts between the coloration of the sides and belly. The fur in alascanus is also 

 of superior quality, and exhibits sufficient difference to make it possible for dealers 

 to distinguish by this means alone whether the skins come from the Commander or 

 Pribilof herds. In the Pribilof seals the claws on the fore flippers are undeveloped 

 being represented by a pit in the skins. 



The true Gallorhinus ursinus has the head and neck slenderer; the females and 

 young males are sooty, rather than brown, the light and dark shades being for the 

 most part equally without ochraceous tints; the belly is usually rather sharply paler 



