CARCINOLOGICAL STUDIES. 19 



basal joint of the external antennae is slightly enlarged 

 and about once and a half as broad as high, 

 and has the anterior margin emarginate for the insertion 

 of the second joint. 



In the male the larger chelipede is on the left, in the 

 female on the right side. In both specimens the arm is 

 sharply trilateral, and the internal as well as the ex- 

 ternal margin of the under surface are armed with several 

 more or less acute small teeth , more developed in the female 

 than in the male , whereas the upper margin is transversely 

 wrinkled. The outer surface of the arm is somewhat gra- 

 nular. The upper surface of the carpus is almost smooth 

 in the larger, but distinctly granulated on the inner and 

 outer sides in the smaller chelipede; the carpus of the larger 

 chelipede is armed with a small acute tooth at the inner 

 angle of its upper surface, that of the smaller with a longer 

 and more acute tooth. The larger hand is about as long 

 as the breadth of the cephalothorax. The upper and espe- 

 cially the lower margin of the palm are granulate, the 

 outer surface is smooth and punctate , the inner surface 

 a little granular. The upper margin of the mobile and the 

 lower margin of the immobile finger of the larger hand 

 are covered with small sharp granules. The fingers of the 

 larger hand of the male are a little gaping, scarcely also 

 those of the female. 



The meropodites of the ambulatory legs are armed with 

 an acute tooth at the distal end of their upper margin. 

 The legs are somewhat hairy and covered , especially 

 on the propodites and carpopodites , with tufts of rather 

 short black hairs. 



This species is most closely allied to Cardisoma arma- 

 Uim Herklots from the western coast of Africa , as is already 

 observed by S. J. Smith , but I may add that it likewise 

 so strongly resembles Card. Urvillei M. E., which inhabits 

 the islands of Samoa , Celebes and the Moluccas , that it 

 also might be misfcakea for this ludiaa species. 



JVotes from tlae Leyden JMuseuca, Vol. XIXI. 



