FEOM THE INLAND SEA OF JAPAN. 395 



joint is 0'84 mm. long. The terminal joint is triangular, 0'8 mm. long and 1'4 mm. 

 broad, almost twice as broad as long and barely shorter than the preceding; its posterior 

 margin is arcuate, convex, the tip rounded. 



The chelipeds (PI. 31. fig. 5) are equal, rather feeble and small ; they are 6 mm. long, 

 almost as long as the upper surface of the carapace is broad. The arm is triangular, 

 2 mm. long, unarmed ; its upper border is strongly curved and carries about in the middle 

 a tuft of long setcs that are half as long as the merus. Stimpson describes the merus as 

 " superne prominentia mediana setigera instructus," but I see no prominence at all. 

 Carpus rounded internally. The chela, which is somewhat compressed and the fingers of 

 which are slightly curved inward, is 3 mm. long, once and a half as long as the merus. 

 The fingers, which are distinctly longer than the upper border of the palm, barely exceed 

 the length of the lower border ; the palm is I'l mm. high, so that the chelae are nearly 

 three times as long as broad. The fingers regularly taper to the pointed acute tips ; they 

 are of equal size, equally broad at tlieir base, and they leave a small interspace between 

 them that gradually narrows towards the tips ; the cutting-edges are rather sharp, that 

 of the immobile finger carries 6 or 7 very low obtuse teeth, nearly of equal size and 

 extending along the two proximal thirds ; the dactylus carries near the base two truncate, 

 somewhat larger teeth, the first of which is little larger than the other, and beyond them 

 the cutting-edge runs somewhat uneven, the distal third excepted. The upper border of 

 the palm is a little hairy and seems to be slightly granular, but it cannot be described as 

 sharp, as was done by Stimpson ; his words " superne acuta " are apparently applicable 

 to the dactylus. The outer surface of the palm and of the fingers is smootli, but a ridge 

 proceeds along the lower border from the carpal articulation to the tip of the index, and 

 the palmar portion of this ridge is granulated. 



As regards their shape and their relative length, the ambulatory legs much agree with 

 those of Tntodynamiajaponica, Ortm. Those of the antepenultimate or third pair (fig. 6) 

 are the longest of all, measuring 11-5 mm., i. e. once and a half the greatest width of the 

 carapace ; the legs of the fourth pair are 11 mm. long, barely shorter than the preceding ; 

 then follow those of the second pair, that are much shorter, measuring 8-5 mm. ; 

 whereas the legs of the fifth pair, 6 mm. long, are the shortest and smallest of all, 

 reaching but little beyond the merus of the penultimate pair. The meri of the third 

 legs are moderately enlarged, as they are almost three times as long as broad ; the two 

 following joints are nearly equally long, and the dactyli are barely shorter than the 

 propodites. The straight dactyli are depressed and taper, about from the middle, to the 

 pointed extremity ; their outer surface is longitudinally grooved in the middle, the 

 lateral margins are ridged, and one observes on either side of the ridges a fringe of stiff 

 outstanding seta3. The lower margin of the outer surface of the merus is coarsely 

 granulated, the arcuate upper border more finely and the borders of the two following 

 joints are also partly granular. The legs of the penultimate pair much resemble those 

 of the third, but the carpo- and propodites are a little broader in proportion to their 

 length ; the dactyli are as long as the propodi, but those of the second pair are a little 

 longer than the propodi, measured in the middle. The dactyli of the small legs of the 

 fifth pair, which are also a little longer than the propodites, are slightly recurved, and they 



SECOND SERIES. — ZOOLOGY, VOL. IX. ^1 



