42 



(2) the abdominal carina ends in a spine, and the sixth tergum has its after 

 edge perfectly smooth instead of quadrispinate : 



(:3) the eye-stalks are larger, and are compressed instead of cyhndrical : 



(4) the chelipeds are relatively stouter, being of much the same proportions 

 as those of the male of Physachseus ctenurus : the arm is compressed and has its 

 lower border very strongly and sharply carinated : the hands are much thinner 

 and more compressed ; the palm having its lower edge, and the fingers their out- 

 side edges, sharply cristate : 



(5) the first pair of legs, not the second, are the longest, and considerably so. 

 Length of carapace 11 millim. Breadth of carapace 9*5 millim. 



Two eo-o--laden females from the Andaman Sea, 271 fathoms. 



The eggs, as in the preceding species, are large and few in number. 



EcHiNOPLAX, Miers. Amended. 



Echinoplax, Miere, Challenger Brachyura, p. 31 : Alcock, J. A. S. B., Vol. LXIV. pt. 2, 1895, p. 178. 



Carapace piriform, inflated, profusely spiny, somewhat constricted behind 

 the eyes. 



Eostrum composed of a pair of spiny horns, between which is a large, verti- 

 cally deflexed, bifid interantennulary spine. 



Eyestalks perfectly retractile against the sides of the carapace, protected, 

 but hardly concealed, by a series of orbital spines : eyes well formed and well 

 pigmented. 



The antennules fold nearly longitudinally. The basal antenna-joint is 

 slender, subcylindrical, and of good length ; though immovable it is perfectly 

 independent ; the antennal flagella are long. 



Epistome broad. The external maxillipeds do not completely cover the 

 buccal cavern, but leave the mandibles exposed between them : the merus is 

 slightly narrower than the ischium, and the coarse palp articulates with its 

 antero-internal angle. 



Chehpeds in the male long and stout, with enlarged hands : in the female 

 short, and not stouter than the legs, with slender hands. 



Legs cylindrical, long, spiny ; their dactyli stout and rather short. The last 

 two pairs much shorter than the first two. 



All seven abdominal terga are distinct in both sexes, but in the adult male 

 the last three, and in the adult female the last two, move as one piece. 



I think that Echinoplax is identical with Ergasticus, A. M. Edw. 



