184 SMITHSONIAN MISCBLIvANEOUS COLLECTIONS 



290. PETROLISTHES HASTATUS Stimpson 



Plate XXII, Fig. 4 



Petrolisthcs hastatus Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 241 

 [79], 1858. 



Carapax above and posteriorly depressed and smooth, anteriorly 

 and at the sides transversely striolated. Front triangular and prom- 

 inent, with the longitudinal furrows sufficiently deep. Marginal 

 lines not conspicuous ; no spine behind the orbit. Crest of the basal 

 joints of the outer antennae prominent, bilobate; inner lobe acute, 

 outer one rounded. Chelipeds regularly but not very strongly gran- 

 ulated above ; posterior margin of carpus not spinulose, but produced 

 into a rather long, curved spine at its outer extremity ; anterior mar- 

 gin of carpus armed with three or four elongated but not very 

 prominent teeth. Ambulatory feet hairy; meros sparsely spinulose 

 above. Outer apex of ischium in the external maxillipeds not pro- 

 duced. Color olive, variable in depth in different individuals, and 

 often minutely mottled with white. Length of carapax in the male, 

 0.47; breadth, 0.46 inch. 



Found in a small harbor at Kikaisima ; also at Ousima. 



291. PETROLISTHES JAPONICUS (De Haan) Stimpson 



Porcellana japonica De Haan, Fauna Japonica, Crust., 199, pi. l, fig. 5. 

 Petrolisthes japonictis Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 241 

 [79], 1858. 



In life this species is of a dark olive color above and bluish- white 

 below. 



It inhabits the lower levels of the littoral zone, and occurred at 

 Simoda in Japan, at the Bonin Islands, at Kikaisima, at the Ama- 

 kirrima Islands, and at Hongkong, in China. 



Genus RAPHIDOPUS Stimpson 



In this form, so distinct from the ordinary PorceUancc, the carapax 

 is rounded, broader than long, and a little projecting at the sides. 

 The front is transverse, not prominent, and tridentate. The eyes 

 are very small and deep-seated. The first or coxal joint of the ex- 

 ternal antennae is very large, joining the superior margin of the 

 carapax, and much produced, far removing the movable portion of 

 the antennae from the orbit. The external maxillipeds are of the 

 usual form ; the ischium, however, is short, very much dilated and 



