FEOM THE INLAND SEA OF JAPAN. 401 



brown, carries anteriorly a small conical tooth or tubercle. Both the outer and the inner 

 angle of the lower margin of the orbits are produced into an acute slender spine that 

 reaches not as far forward as the eye-peduncles ; the outer wall of the orbits carries on 

 its free border a small spine, which is preceded on its outer surface by a somewhat larger 

 one. The outer wall is separated on each side by a furrow from the front and from the 

 pointed spine at the outer orbital angle ; the latter spine carries a small acute tooth on 

 its outer margin (PI. 31. figs. 10 & 11). 



The lateral margins of the buccal frame are considerably thickened anteriorly at the 

 level of the merus-joint of the outer footjaws and terminate in a forwardly-directed 

 spine that reaches as far forward as the spine at the internal angle of the orbits. The 

 outer footjaws are granulated, like the lower surface of the carapace. The merus-joint, 

 measured along the inner border, appears to be 1 mm. long, the ischium-joint 1-6 mm. ; 

 the former is thus more than half as long as the latter. 



The 5-jointed, strongly granulated abdomen resembles that of Arc. ll-sphwsa, de Haan ; 

 the same rather coarse granulation exists on the sternum. The chelipeds, 13 mm. lone, 

 are little more than once and a half as long as the carapace. The merus-joint, which is 

 a little stouter than that of Arc. W-spiiiosa, de Haan, is covered above with rounded, 

 circular granules, mostly large, though with some smaller observable among them on 

 the distal half ; on the anterior border they are of a more conical shape and the posterior 

 border carries four strong, nearly equidistant, and suhequal, subacute spines, which 

 are not described by the quoted authors, unless by Stimpson with the words " o-ranulis 

 plerumque subspiniformibus." Similar circular bead-like granules as on the upper 

 surface also occur on tiie lower. Carpus and hand are closely beset with granules, which 

 are, however, much smaller than those of the arm ; the slender fingers, which shut close 

 together and are almost once and a half as long as the upper border of the palm, are 

 deeply furrowed longitudinally ; they show a fine granulation under a strong magnifying, 

 glass, they are a little hairy distally, and their prehensile edges are beset with numerous 

 small teeth, a few of which are distinctly larger on the distal half of the finders. 



The ambulatory legs, smooth to the naked eye, are indeed covered with a close minute 

 granulation, visible only by means of a strong magnifying-glass ; the anterior border of 

 the meropodites is spinulose, being beset witli 5-9 small, spiniform, acute teeth, and the 

 slender, slightly arcuate terminal joints are about as long as the propodites. 



This pretty little crab has the front and a median band on the upper surface of the 

 carapace white, the median band being half as broad as the front ; adjacent to the band 

 the upper surface is orange, but this colour gradually becomes paler laterally. The 

 spines are also of a pale orange-colour, but those that stand on the band are white. 

 The lower surface is uncoloured, but the sternum is marked anteriorly, on each side of 

 the abdominal groove, ivith a triangular orange-coloured fleck, between that groove and 

 the base of the chelipeds. The latter are pale reddish above ; the proximal extremity of 

 the merus is white, like the tips of the fingers. The ambulatory legs are uncoloured, 

 but carpus and merus are partly reddish. 



Arcania 11-spinosa is at once distinguished by the different shape of the front, by the 

 carpus and chelae being apparently smooth, and, no doubt, by other characters as well. 



