418 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 
the female, although having the same markings, is of a light, almost 
silvery, hue. The whiskers are crenulate. The nails are of moderate 
size and of a brown tint. 
The Ribbon Seal has been imperfectly known since 1781, but the first 
description of any considerable fullness is that of Von Schrenck, pub- 
lished in 1859.* This observer, however, was unable to obtain the skele- 
ton and the characters of the latter, except so far as the teeth were con- 
cerned, have until recently remained undescribed. In a paper upon 
the mammals collected during the ‘‘ Vega” expedition, published some 
months ago by Nordquist,t the skull is described somewhat at length 
and three imperfect figures are given. 
The genus Histriophoca was established by Dr. Gill in1873, upon the 
basis of Von Schrenck’s observations of the exterior and teeth.{ His 
diagnosis is as follows: “The structural (and especially dental) char- 
acters of this species, according to Von Schrenck, indicate a generic 
distinction from all the familiar forms of the subfamily Phocine. The 
molars (except the first) are two-rooted as in the typical Phocine, but 
in external form are simply conic or have rudimentary cusps, thus re- 
sembling Halichwrus. The genus may be named Histriophoca.” 
In July of the present year, at which time the cleaned and mounted 
skeleton was received from Rochester, I published a faller and some- 
what different diagnosis of the genus.§ 
After more prolonged study of the skeleton, and comparison with 
those of other species, I am somewhat in doubt as to the relationships 
of this seal. The skull presents remarkably close affinities to that of 
Phoca foetida, the representative of the subgenus Pusa, as defined by 
Professor Allen. The most absolute differences are in the shape of the 
alveolar border of the maxillary, which is curved ventrally and laterally 
in Histriophoca, but is practically straight in Pusa, and in the number of 
sacral vertebree, there being four in Pusa and three in Histriophoca. There 
are also a number of relative differences, of which the most salient are as. 
follows: The accessory cusps of the molars are less developed in Histrio- 
phoca than in Pusa. The tibia is less curved in the former than in the 
latter, the crest of the ileum is more everted and the sexes vary more 
in color. The rooting of the molars in Histriophoca is different from 
that which obtains in any of the subgenera of Phoca, in being variable. 
The first two, and possibly the third, would seem to be single-rooted in 
the majority of cases. 
If the taxonomy of the Phocids proposed by Professor Allen in his 
recent admirable work is accepted, none of the characters which have 
been enumerated are sufficient to raise ee gee? to genericrank. In 
* Von Bulmeacts melee in el Tantien " 1859, p. 182, Pl. IX, Figs. 1-3 (anineal); 
+ Vega-Expeditionens Vetenskaplica Taleb tneeliion: Andra Bandet, 1883, pp. 107-111, 
Figs. 16-18. 
t American Naturalist, vii, 1873, p. 179. 
§ American Naturalist, xvii, 1883, p. 798. 
