“THE SUBSPECIES OF FUR SEAL. 45 
THE ROBBEN ISLAND HERD. 
The third herd is resident in the Sea of Okhotsk on Robben Island, where a 
considerable remnant still exists, and formerly occupied other rookeries, now virtually 
extinct, on four islands of the Kuril group—Musir, Raikoke, Srednoi, and Broughton. 
The mipnation route of this herd lies in the inland sea of Japan. 
THREE DISTINCT SPECIES. 
The fact that the seals of the Pribilof herd differ from those of the Commander 
Islands in color, in form, and in character of the fur-has long been recognized. These 
‘differences, though slight, are permanent and constant. As 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 that the herds represent 
distinct species. As the Komandorski seals formed the type of Callorhinus ursinus, 
the Pribilof seals may: be taken to represent a new species, to which the name 
Callorhinus alascanus may be given, and the Robben Island herd, likewise different, 
may be called Callorhinus curilensis. 
CALLORHINUS .ALASCANUS. 
The description of this new species or subspecies is given in full in a special paper 
which appears in Part III. It may be noted here that 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 females and the young males, by the more silvery color of the 
gray pups, which have the whitish patches on the rump less than in wrsinus. In 
general it shows a lack of sharp contrast between the coloration of the sides and belly. 
The fur is of superior quality and exhibits sufficient difference to make it possible for 
the dealers handling the skins to distinguish them by this means alone. In alascanus 
the claws on the foreflipper are undeveloped, being represented by pits.in the. skin. 
CALLORHINUS URSINUS. 
The true ursinus has a slenderer head and neck. The females and young males 
are sooty rather than brown, the light and dark shades being alike for the most part 
without ochraceous tints. The belly is usually rather sharply paler than the back, 
and the gray pup is more brownish and less gray than in the Pribilof animal, having 
a pale patch on each side of the rump. The fore feet have two or three raaimentary 
claws. 
CALLORHINUS CURILENSIS. 
The seal of Robben Island and the Kurils, differs from both of the foregoing in 
the whitish color of the under fur. This is rusty brown in ursinus and alascanus. It 
is said also to have a broader head than ursinus and to exhibit other differences in 
the quality of the fur, distinguishing the seals of Robben Island from either of the 
other herds. 
In the following discussion our attention will be directed chiefly to a consideration 
of the Pribilof Islands seals. In Part IV of thisreport the herds of the Komandorski 
and Kuril islands will. be discussed in detail. 
