CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 185 



rounded within, and its external apex is not produced. The cheh- 

 peds are not broad and depressed, but thick; the hands are about 

 equal, but not large, so that they do not touch each other when the 

 chelipeds are folded against the face. Finally the dactyli of the 

 ambulatory feet are of a shape remarkably different from anything 

 yet observed in the family ; instead of the short, thick, curved form 

 observed in all other genera, we have a straight, slender, elongated 

 terminal joint shaped like a stiletto or a flattened needle, and sharply 

 pointed, but without any indication of a distinct unguiculus. This 

 form of feet is well adapted to the habits of the animal, enabling it 

 to move wdth facility through the soft mud in which it lives. 



It is an inhabitarit of moderately deep water, and the only known 

 species is found in the Chinese seas. 



2 2. RAPHIDOPUS CILIATUS Stimpson 



Plate XXII, Fig. 5 



Raphidopiis ciliatiis Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 241 

 [79], 1858. 



Sides of the body and margins of the feet thickly ciliated with 

 long, fine hairs. Carapax pubescent, somewhat areolated ; surface a 

 little uneven, and transversely rugate. Lateral margin strongly con- 

 vex, with, a fissure behind the base of the external antennae, two 

 .small teeth or spines near the middle, and a spine on the postero- 

 lateral margin at the extremity of a short oblique ridge. Frontal 

 teeth minute, the median one most prominent. Anterior margin but 

 slightly sinuated at the orbits. Latero-inferior regions of the cara- 

 pax strongly striated or longitudinall}- ridged, especially posteriorly ; 

 ridges few in number and subdistant. The external antennae are 

 four or five times as long as the carapax and folded backwards. 

 Chelipeds large, angular, and very hairy ; meros large, more than 

 two-thirds as long as the carpus, roughened above and armed below 

 with a single long, sharp, curved spine : carpus about two-thirds as 

 long as the hand, roughened above, with a median longitudinal spinu- 

 lated ridge, its anterior margin not dilated, slightly concave and 

 serrulated ; its posterior margin convex and armed with five spin- 

 ules ; smaller hand elongated, subtriangular, with three longitudinal 

 obtuse ridges, minutely crenulated or spinulated. on the upper sur- 

 face ; fingers longer than the palm, not gaping, tips much curved, 

 crossing each other, inner edges minutely denticulated but not 

 toothed ; inner edge of immovable finger slightly dilated. In the 

 larger liand the dactyhis is subcristate above, with a slightly promi- 



