00 STALK-EYED CRUSTACEA. 
branaceous, as in the genus Dermaturus Brandt.* In all essential structural 
features, however, it agrees with the preceding species Piel ode asper ) 
and conforms to the genus Leptolithodes. 
A Leptolithodes, in some respects intermediate between L. longipes and 
L. asper, inhabits both the east and west coasts of the North Pacific (British 
Columbia and Japan). From this species (which is apparently undescribed) 
both ZL. longipes and L. asper of the tropical Pacific coast of America are 
probably derived. 
LITHODES Larr. 
Gen. Crust., I. 39, 1806. 
Lithodes panamensis Fax. 
Plate X., Hig. AS Le. 
Bull. Mus. Comp. Zo6l., XXIV. 166, 1893. 
Carapace subpiriform, of about equal length and breadth; gastric and 
branchial regions very convex; a deep depression on each side at the an- 
terior limit of the branchial areas, and another between the gastric and 
cardiac areas. Rostrum cylindrical, terminating in three spines or teeth, 
one of which is median, the other two lateral; a long horn, slightly up- 
curved, is given off from the lower side of the proximal end of the rostrum. 
The whole surface of the carapace is rough with low warty protuberances ; 
the gastric region bears two pairs of spines, the anterior pair separated by a 
greater interval than the posterior pair. Two small spines on each branchial 
area and two on the intestinal region. The orbit is bounded externally by 
a prominent spine, and there are five more spines on the lateral border of 
the carapace ; viz., one at the antero-lateral angle, one on the hepatic region, 
and three on the branchial. Besides these, there is a rudimentary lateral 
spine near the anterior limit of the branchial region. The posterior margin 
of the carapace is tubereulated, not spinose. The third segment of the anten- 
nular peduncle is equal to the first segment in length and considerably 
longer than the second segment. The antenne are about equal in length to 
the carapace without the rostrum; the second segment is armed with a long 
and sharp external spine ; there is, moreover, on the antenna of the right 
side a movable thorn-like acicle equal in length to the last two segments of 
* Bull. Phys.-Math. Acad. Impér. Sci. St. Pétersbourg, VIII. 268, 1850. 
‘o- 
