656 MR. W. F. LANCHESTER OS THE [DeC. 3, 



A female. 



This species is closely related to G. pacliydadyla A. M.-Edw. 

 (c/. Xouv. Arch. Mus. t. vi. p. 86, pi. ii. tig. 1), while presenting 

 at the same time several differences which clearly mark it off as a 

 distinct species. It resembles that species chiefly by the extreme 

 shortness of the carpal joint in the 1st pair, and the general 

 smootlniess of surface in that pair, and, as well, in the fairly 

 strong development of the telson ; but differs notably in the fact 

 that the external maxillipedes are even more pediform, and that the 

 merus of the 1st pair is quite unarmed, no trace of denticulation 

 being found anywhere on the leg. 



The rostrum and eyes are as in C.pac7i</(?aci!yZa, though the point 

 of the rostrum appears blunter in our species. 



The eyes reach beyond the middle of the 1st antennular joint ; 

 the 3rd joint of the antennular peduncles is barely twice as long as 

 the 2nd, and their flagella 2-3 times as long as the 3rd joint and 

 about two-thirds the length of the carapace„ 



In the antennal peduucles, the 3rd joint is twice as long as the 

 2nd, and the latter twice as long as the 1st ; the flagellum is a 

 little longer than the carapace. The 3rd maxillipedes are pediform, 

 the carpal joint alone being slightly dilated ; the ischium is 

 regularly and evenly denticulated on its inner edge ; the denti- 

 culations being very small and best seen with a lens. 



The larger chelipede is entirely smooth, except for a well-marked 

 line of hairs on the inner upper edge of the hand and dactyl, a few 

 more scattered hairs on their under edge and outer surface, the 

 coarse denticulation of the fingers, on each of which one tooth is 

 more prominent than the rest, and a A'ery short, bluntly 3-toofhed, 

 forwardly directed ridge on the under distal angle of the carpus. 

 The ischium and merus are the same length (4 mm.); the ischium 

 long and narrow, the merus broad and swollen, with a very blunt, 

 but still distinct, ridge on its outer surface. The carpus is much 

 shorter than the palm (carpus 1*75-2 mm., palm 5 mm.), but of 

 nearly the same depth vertically, = 3 ram. ; the fingers are a little 

 shorter than the palm, = 4 mm. In the smaller chelipede, which 

 is longer and slender, the carpus is 3 mm. long, the palm 4 mm., 

 and the fingers 2 mm. ; this appendage also is quite smooth. The 

 2nd pair are as in C. pachi/dactyla ; in the 3rd pair, however, the 

 posterior edge of the propodite is not scooped out as in that species, 

 rather the joint is barrel-shaped (see fig. 2). 



Of the abdominal segments, the 1st is the shortest, the 2nd and 

 3rd the longest, equal or nearly so, the 4th, 5th, and 6th a little 

 shorter than those preceding ; the telson is the same length as the 

 1st abdominal segment, rounded and smooth above, and somewhat 

 shorter than the uropods, the inner joints of which bear a longi- 

 tudinal ridge down the middle of their upper surfaces. 



Yvoia C. amboinensis de Man (ef. Arch. f. Naturg. liii. i. p. 480, 

 pi. XX. fig. 4), which is, figain, a closely allied species, C. secura 

 differs : (a) in its much shorter carpus ; {b) in the much shorter 3rd 

 joint of the antennular peduncle ; (o) in the ridged surface of the 



