Tas PROCEEDINGS OF THE NATIONAL MUSEUM. 225 
side of this groove are double rows of sharp spiny granules; the space 
between is filled with short, stout, curved bristles. The lower margin 
of the dactyls has one double row of these granules; the space between 
is also set with sharp bristles. 
The numerous specimens of this species in the collection are without 
doubt identical with T. serratus of White. White’s figure represents 
an imperfect male, the front is not well defined, and the greater part of 
the hair is gone, yet it isa graphic picture of some individual speci- 
mens. 
Dana’s figures are not characteristic, representing as they do an im- 
mature female. A female in the collection, with an undeveloped abdo- 
men, might almost have served for the originalof the figures, except 
that the inner angle of the eye is much straighter than in his figure. 
The identification of this species with the Cancer cheiragonus of Tile- 
sius is not quite so satisfactory, but, all things considered, the evidence 
seems to be, if not conclusive, at least strong. 
Brandt described Platycorystes ambiguus in 1848, and in 1851 deter- 
mined this to be identical with Cancer cheiragonus of Tilesius; after- 
wards, with White’s description and figures before him, identified White’s 
species with his. The peculiar short, coarse hair of even length with 
which this crab is ordinarily well covered, not unlikely suggested the 
name Hippocarcinoides to Steller at one time and Cancer pilosus at an- 
other, while the arched and produced inner angle of the eye as seen 
from above suggested the name of Cancer auritus. 
The specimens in the collection, over one hundred and fifty in num- 
ber, came from Oregon and north along the Alaskan coast, from several 
of the Aleutian Islands, and one from Bering Island, near the coast of 
Siberia. If a species liable to be confounded with cheiragonus existed 
in this locality, it would probably be represented by one or more speci- 
mens. Steller’s and Brandt’s specimens were obtained in the same 
region. ; 
The finest lot from one locality were collected by Dr. T. H. Streets, 
U.S. Navy, at Kasa-an Bay, Prince of Wales Island, southeastern 
Alaska; ten specimens in all; five males, of which the smallest is 49 
millimeters in length by 65 in breadth, the largest 63 millimeters in 
length by 82 in breadth; five females, of which the smallest is 45 by 58, 
millimeters; the largest, 57 by 74, millimeters. 
The reproductiveopeningsin the females of this genus are placed out- 
side of, or rather out from under, the abdomen. At these openings the 
sternum is thickened and verysolid. The opening itself is funnel-shaped, 
spreading out into an ear-like depression, the sidesof which are thickened 
and elevated above the surrounding surface of the sternum. In the 
immature female the sixth segment of the abdomen has slightly con- 
cave edges. In the mature female the abdomen has expanded greatly, 
except the seventh segment and two-thirds of the sixth, which in an 
individual case measures 16 millimeters near the articulation with the 
Proc. N. M. 92 15 
