41 8 BULLETIN OF THE BUREAU OF FISHERIES. 



extended its range far northward in this favorable locality. The creature is said to conceal itself by 

 holding a flat or concave piece of living sponge upon its back, but in none of the Beaufort specimens 

 was the habit observed. One perfect specimen brought up in the dredge was clinging to the branches 

 of a Gorgonia. It was carried alive to the laboratory, where it was kept for several days in a small 

 aquarium. It spent the entire time huddled up in a comer and showed no interest in anything except 

 some fragments of oyster which were thrown in for it to eat. 



Genus HYPOCONCHA GuSrin Meneville. 



Hypoconcha Gu^rin M^neviUe, 1854, p. 333. 



KEY TO THE SPECIES OP THE BEAUFORT REGION. 



a. Anterior margin of carapace without spines arctiata. 



aa. Anterior margin of carapace with several strong spines sabulosa. 



Hypoconcha arcuata Stimpson. PI. xxxi, fig. 2. 



Hypoconcha arcuata Stimpson, 1859, p. 72; Benedict. 1901, p. J33. 



Body short, broad, flattened; dorsally with a thin, parchmentlike covering, ventrally solid and 

 roughly granulate, the appendages capable of being folded compactly against the body. Front margin 

 of carapace nearly semicircular in outline; the margin densely ciliated, deeply fissured in the middle, 

 and with a shallow notch on each side near the middle; ventral stirface without ridges, sloping evenly 

 to the anterior margin, and with eyes, antennules, antennae, and mouth parts deeply seated in de- 

 pressions in its surface; a narrow fisstire in front of the eye, for the lodgment of the flagellum of the 

 antennary flagellum; outer posterior margin of orbit fissured. Third maxillipeds completely closing 

 the buccal cavity. Legs all stout, hairy, and coarsely granulate; the first pair chelate, the fingers 

 somewhat spatulate and toothed at the tip, the thumb set on at an angle with the hand; second and 

 third legs with sharp, corneous tips; fourth and fifth legs borne on the dorsal siu-face, their penultimate 

 segment very short, and the terminal segment reduced to a little curved claw. Abdomen short, flexed 

 so that its last two segments lie on the thoracic sterna. 



Length of a male, in nattu'al position, 33 mm.; carapace, 24 mm.; width of carapace, 24 mm. 

 \- Color, gray. 



This curious little crab has so far been obtained only in the dredge in Bogue Sound, off Morehead 

 City. It is always found occupying a valve of some lamellibranch shell, preferably, it seems, a clam 

 shell, which it carries about upon its back, after the maiuier of a hermit crab. By means of the claws 

 on its fourth and fifth pairs of legs, aided, perhaps, by the pressiu'e of its body against the shell, it clings 

 so tightly that it is almost impossible to remove the live animal from its abode without crushing it. 



Hypoconcha sabulosa (Herbst). PI. xxxi, fig. 3. 



Cancer sabulosus Herbst, 1799, vol. n, p. 57. 



Hypoconcha sabulosa Gu^rin Meneville, 1854, p. 333; Stimpson. 1858, p. 226; ibid., 1859, p. 72; Benedict, 1901, p. 133. 



In form and general appearance very similar to H. arcuata, but with the ventral surface nodulose 

 as well as granulate, and marked by several strong ridges. The anterior margin of the carapace is not 

 so deeply fissured, the notches above the antennae are scarcely evident, and toward the middle, beneath 

 the fringe of setae, there are several strong spines. The antennary fosss are limited in front by a pair 

 of strong, oblique ridges, which arise between two of the spines of the anterior border, meeting each 

 other in the middle line at the front of the epistome. The posterior border of the epistome is raised into 

 a prominent ridge, which is continued on either side across the front and some distance along the sides 

 of the buccal area. The basal articles of the antennae are tuberculate; the basal one has a strong, in- 

 wardly directed tooth and the terminal one a tooth on each side of the base of the flagellum. The fissure 

 in the outer margin of the orbit is very noticeable, owing to the development of a strong tubercle on 

 either side of it, the one lying just behind the eye being especially strong and spiniform. The carpal 

 segment of the first pair of legs bears several dentate tubercles. 



Length of a female, in natural position, 33 mm.; carapace, 22 mm.; width of carapace, 22 mm. 



Color, gray. 



This species occurs in Beaufort harbor, but is apparently less common than H. arcuata. In habits 

 the two species, so far as is known, are similar. 



