DECAPOD CRUSTACEANS OF THE BEAUFORT, N. C, REGION. 46 1 



individuals are slightly divergent at the tip. The grooves of the dorsal surface are deep and their surface 

 is finely punctate. The elevations of the carapace are as follows: One gastric, placed longitudinally, 

 a small circular lobe on each side; a cardiac, placed transversely with a deep notch on each side pos- 

 teriorly; an intestinal, the outer ends of which extend outward along the posterior margin; a lateral, 

 paired, extending from the lateral angle forward nearly to the eye; a small post ocular and a larger 

 supraocular elevation on each side; the margins of these elevations are sharply defined and the surface 

 is finely eroded. 



Chelipeds rather small and weak. First pair of walking legs longer than any of the others and 

 exceeding the chelipeds by more than the length of the dactyli. 



Measurements of a male: Total length, 21 mm.; rostrum, 13 mm.; extreme width, 10 mm. 



Color, orange red. 



Foiu- specimens of this remarkable little crab were brought in by the Fish Hawk from a depth of 

 about 100 fathoms, 30 miles south of Cape Lookout. It has been recorded by Dr. Mary J. Rathbun 

 from 90 fathoms ofif Cape Fear. In the specimens at hand an interesting variation is shown in the ros- 

 trum. In the largest individual, a female, the two horns extend straight forward and are in contact 

 except close to the tip ; their length is exactly equal to the extreme width of the carapace. In the next 

 specimen, a male, the horns are proportionally longer, ctirved outward and are divergent for about the 

 terminal half. In the next individual the horns are considerably shorter than the width of the cara- 

 pace and in close contact throughout their length. In the last individual, 8 mm. wide, the location 

 of the horns is occupied by a single conical process showing no indication of bifurcation. 



Genus TYCHE Bell. 



Tyche Bell, 1836a, p. 57. 



Tyche emarginata White. PI. xxxix, fig. 4. 



Tyche emarginata Wliite, 1847, p. 206; Stimpson, 1871, p. 119; A. Milne-Edwards, 1S73. p. 126. 

 Platyrkinchus irUuberciUaius Desbonne and Schramm. 1867, pi. m. figs. 7, 8. 



Carapace about one and two-thirds times as long as wide, irregular and angular, prolonged in front 

 into four long, cylindrical, ciu-ved horns, the median pair belonging to the rostrum and the lateral one 

 springing from above the eyes; from the front the carapace slopes abruptly upward, the gastric regions 

 being concave, to an irregularly octagonal dorsal area which has nodulose lateral borders and which is 

 prolonged behind into a laminiform expansion that overhangs the base of the abdomen and the basal 

 articles of the walking legs. The anterior margin, behind the base of the supra-orbital horns, is lamini- 

 form and divided by a deep, narrow fissure. 



Eyestalks long, but projecting very little beyond the margin of the carapace. Antenna concealed 

 beneath the front. Third maxillipeds with the exopodite provided with a hook which overlaps the 

 base of the ischium of the endopodite ; ischium and meros with similar interlocking processes. Chelipeds 

 short and weak. Walking legs of moderate size, their dactyli very long and slender. 



Length, posterior margin to base of rostrum, 28 mm.; width, 20 mm. 



A single specimen of this ctnious crab was brought in by the Fish Hawk from the fishing grounds 

 (station 7944) where it was dredged in about 14 fathoms. It was completely overgrown with sponge, 

 hydroids, bryozoans, and worm tubes, the entire mass being twice or three times the size of the crab. 

 After the removal of as much of the foreign growth as could be taken off without injury to the specimen 

 it proved to be a female with her abdominal pouch filled with eggs. 



Family PARTHENOPIDAE. The long-armed crabs. 



Oxyrhyncha having the chelipeds much larger than any of the other legs and with 

 the fingers bent on the hand at an angle toward the side on which the immovable finger 

 is set, the second article of the second antenna small, short and not fused with the 

 epistorae or the front, the orbits well formed, and hooked hairs very seldom present. 



This family comprises 17 genera, of which 4 are represented in the Beaufort fauna. 

 69571°— 18 30 



