28 
Natural History 
simple, furnished on the sides only with spines arranged somewhat in rows. 
Thorax triangular, very high, and its front part is only half as wide as the 
back part. The gastric and genital regions are confluent, and very convex ; 
the cardiac and intestinal regions are equally confluent, but separated from 
the branchial and genital region by a very deep semi-lunar fossa. 
The carpus of the first pair of feet is evenly crested along the upper and 
inner margin. 
R, W OSNESSENOKII. PI IV. 
This, the only known species, is represented in the Provincial Museum, 
Victoria. 
Tribe HAPALOGASTRINEA. 
The basal or anterior abdominal ring, and the two apical rings especially, 
furnished merely with very thin calcareous laminae, all the remaining parts 
being soft. The sides of the abdominal portion are not received by the 
sternnm, but conceal the basal joints of the feet. 
Genus Hapalogaster Brandt. 
Melanges Biologiques, Vol. I., 1850, p. 58. 
The two apical joints of the external maxilhpeds very greatly attenuated 
at the base so as to appear pedicellate ; last joint but one much dilated at 
the apex and subtriangular. The shell of the thorax is thin, almost mem- 
branous, but strengthened evenly and extensively with calcareous matter, 
nearly heart-shaped, strongly arched and convex on the sides of the posterior 
half, with four spines on the sides of the anterior half. The branchial 
regions are very marked but confluent with the intestinal region. The 
anterior ring of the abdomen covered on each side with a thin calcareous 
lamina which is transverse, straight, with four rounded angles, without any 
furrows, and, furthermore, furnished between the said lamime themselves 
with a thin, narrow, oblong lamellula which is conspicuous in the middle of 
the back. 
Hapalogaster inermis Stimpson. 
Ann. Lyc. Nat, Hist., New York, VII., p. 243, 1860. 
Smith, S. J., Report of Geol. Surv. Can., 1878-.79, p. 211 B. 
Carapax longer than broad, nearly smooth above, margins unarmed and 
smooth. Rostrum convex above, almost carinated, apex scarcely acute. 
Feet subcylindrical, almost naked, rugose above, with minute setose 
tubercles. Plates of first segment of abdomen narrow. Length of carapax 
0.4"; width posteriorly 0.38". 
A specimen was collected by Dr. Dawson in the Queen Charlotte Islands. 
In this the chelipeds are very unequal, the right being twice as stout as the left, 
much less setose, and the excavated fingers are without horny tips. — (S. J. 
Smith.) 
