MUSEUM OF COMPARATIVE ZOOLOGY. 17 



The chelipeds are slender and very neatly equal in length, but the right is 

 very much stouter than the left. In the .right cheliped the merus and carpus 

 are subetiual in length, together nearly twice as long as the carapax, and both 

 are rough and obscurely spinous, the spines being most conspicuous on the 

 edges of the upper surface of the carpus, which is fully three times as long as 

 broad, flattened ab6ve, and angular, but not distinctly carinated along either 

 side. The chela is not far from twice as long as the carpus, nearly three times 

 as long as broad, compressed vertically, evenly rounded, smooth and nearly 

 naked above, but clothed with long, soft hair beneath ; the digits are longi- 

 tudinal, not gaping, and the dactylus is about two thirds as long as the basal 

 portion of the propodus, and its prehensile edge is armed with a broad tooth 

 near the middle. In the left cheliped the merus and carpus are similar to 

 those of the right, but much more slender and a Uttle longer ; the carpus is 

 about six times as long as broad, and the edges of the upper surface are rather 

 more sharply angular than in the right ; the chela is shorter than the right, but 

 very slender, smooth, and nearly naked ; the digits are similar, longitudinal, 

 slightly longer than the basal portion of the chela, compressed, slightly curved 

 downward toward the tips, but the pi-ehensile edges straight and very minutely 

 serrate. 



The ambulatory legs are very nearly equal in length, and slightly overreach 

 the chelipeds ; the merus is about as long as the left chela, and roughened with 

 small spines on the upper and under edges ; the propodus is shorter than the 

 merus, compressed, smooth, and ciliated along the edges ; the dactylus is a 

 little longer in the second than in the first pair, but in both shorter than the 

 propodus, very strongly compressed, very slightly twisted, about ten times as 

 long as broad, and thickly ciliated along both edges, except for a short distance 

 along the lower edge near the tip. 



The female is smaller than the male, and has proportionally shorter am- 

 bulatory legs, and chelipeds vary much shorter and much more alike. The 

 right chela is only about a third longer than the carpus, little more than a 

 third as broad as long, and the digits are slender and nearly as long as the 

 basal portion. The left cheliped is proportionally stouter than in the male, 

 and thus approximates to the right ; the chela itself is scarcely more than a 

 third longer than the carpus. The ambulatory legs overreach the chelipeds 

 by nearly or quite the full length of the dactyli, but all the segments have very 

 nearly the same relative proportions as in the mat5. 



The eggs are few in number and very large, being about a millimeter in 

 diameter in alcoholic specimens. 



In young males the chelipeds and ambulatory legs are similar to those of the 

 female. 



Two specimens from Station 314 give the following measurements : — 



Sex $ 9 



Length from front of carapax to tip of abdomen . ^ 18.0 mm. 15.0 mm. 

 " of eye-stalks 2.8 2.5 



VOL. X. — NO. 1. 2 



