CARCINOLOGICAL STUDIES. 45 



and distinctly crenulate along its whole length ; the lower 

 orbital margin of Gelas. inversus^ however, is slightly 

 concave in the middle and quite entire, except 

 towards its external rounded angle, which ap- 

 pears somewhat crenulate. In both species the orbits 

 present no trace of an accessory row of granules near the 

 lower orbital margin. 



The larger chelipede of the male is characteristic. The 

 anterior margin of the arm is somewhat granulate in Gelas. 

 lacteus , but in Gelas. inversus this margin is dilated distally 

 in a longitudinal lamellate crest, which appears 

 somewhat denticulate. The upper surface of the wrist is 

 somewhat granulate , its inner margin finely denticulate , 

 its outer surface nearly smooth. The larger hand has about 

 the same form in both species , being three times as long 

 as high, and the fingers being scarcely more than once 

 and a half as long as the palm. 



In Gelas. inversus the palm is a little longer than high, which 

 is also the case in the other species. The upper border of 

 the palm is slightly rounded in the Japanese species , but 

 in Gelas. inversus this border is somewhat flattened, 

 though also granulated, and separated exter- 

 nally from the outer surface of the palm by a 

 longitudinal row of granules. The upper half of 

 the outer surface of the palm is rather coarsely gra- 

 nulated , but in Gelas. lacteus this granulation is much 

 finer: in both species the greater under half of the palm 

 appears smooth for the naked eye, very finely granulate 

 under a lens of sufficient power. The lower sharp margin 

 of the palm is distinctly granulate in Gelas. inversus , but 

 very finely so in the other species. The fingers are smooth 

 for the naked eye , and present about the same form and 

 length in both species. They are nowhere furrowed, neither 

 in Gelas. lacteus nor in Gelas. inversus. 



The granulation at the base of the dactylus is a little 

 coarser in the species of Hoffmann than in the other. 

 The mobile finger of Gelas, inversus is constantly 



Notes from the Leyden M.useiim, "Vol. XIII. 



