CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 183 



It is very common on the shores of the Western Pacific, ranging 

 in station from low-water mark to above half-tide level on rocky and 

 stony ground. It was found by us in Kagosima Bay, at the Bonin 

 Islands, at Ousima, and on the outer shore of' Hongkong Island. 



289. PETROLISTHES PUBESCENS Stimpson 



Plate XXII, Fig. 3 



Pctrolisthcs pubcsccns Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 241 

 [79], 1858. 



The carapax and feet are everywhere pubescent above. The 

 margins of the feet, and particularly the outer margin of the hands, 

 are densely ciliated. Carapax subovate, very slightly longer than 

 broad, sides rounded, and not margined with an elevated line, but 

 armed with a minute spine in the post-orbital sinus. Front some- 

 what trilobate ; median lobe largest, rounded, and sufficiently promi- 

 nent. Suborbital margin not deeply concave. Basal crest of outer 

 antennae much projecting. External apex of the ischium in the 

 external maxillipeds not produced. The chelipeds above are nearly 

 smooth beneath the pubescence, but in part minutely and sparsely 

 spinulose ; meros spinulose above ; front margin of carpus five- 

 or six-toothed, the tooth being alternately large and small, the 

 large ones sometimes denticulated, inner tooth largest, no tooth on 

 the part next the hand ; a few spinules along the posterior side of 

 the carpus ; outer margin of the hand armed with ten small spines 

 above the marginal series of cilise ; superior edge of dactylus denticu- 

 lated. Upper margin of the meros-joint in the ambulatory feet 

 spinulose. Color above bluish-white, distantly and regularly spotted 

 with purplish-brown, the carapax having four spots about the mid- 

 dle and others about the margin ; feet each with four or five spots ; 

 beneath white. Length of carapax in the male, 0.31 ; breadth, 

 0.295; length of larger hand, 0.46; breadth, 0.19 inch. 



\'ery near to P. toincntosa Dana (loc. cit., i, 420, pi. xxvi^ fig. 10), 

 but the carapax is broader, with a more depressed and even surface ; 

 the outer margin of the hand is spinulose along the whole length; 

 the outer maxillipeds are not smooth, but transversely lineolated, 

 and the meros of the ambulatory feet is spinulose above for the whole 

 length. 



Found under large stones on the ocean shore of Foukow Bay, 

 Ousima. 



