CARCINOLOGICAL STUDIES. 233 



nulated edge. The outer surface of the palm is somewhat 

 granular near the articulation with the wrist, especially 

 that of the smaller hand , and in both hands the furrowed 

 fingers are somewhat granulated at their base. 



The ambulatory legs resemble those of the Mergui spe- 

 cies , but the terminal joints are slightly longer than the 

 propodites. 



I give the measurements of four male specimens: 



millimetres. 



1. 2. 3. 4. 



Length of the cephalothorax 14 ^ 14^ 13^ II4 



Breadth of the cephalothorax (distance between the 



third antero-lateral teeth) 19^ 19^ 18^ 154 



Distance between the internal orbital angles ... 6 5^ 5^ 44 



Length of the larger hand (fingers included). . . 16 19 15y 15 



Length of the palm g*. 11^ 10 9 



Height of the palm near the articulation with the 



fingers 8 91 8 7^ 



Heterop. Vauquelini Aud., of which a male specimen 

 from the Red Sea lies before me , may be distinguished 

 from Heterop. tridentata by the following characters : the 

 front is somewhat broader, the distance between the in- 

 ternal orbital angles being somewhat broader than a third 

 of the width of the cephalothorax; it is rather deeply 

 emarginate on each side of the small triangular median 

 incision , and , consequently , the front consists of two pro- 

 minent, broad and rounded internal and of two external 

 lobes, the latter being much smaller, dentiform and pro- 

 jecting much less forward i. e. downward. The protogastric 

 and mesogastric regions are not marked with transverse 

 ridges , as in Heterop. tridentata , but they are smooth , and 

 no granulated crests are seen in this species on the frontal 

 lobes, immediately behind their anterior margin, so that 

 in Heterop. Vauquelini the front does not appear bimar- 

 ginate. The upper margin of the arm of the larger cheli- 

 pede of the male terminates into an acute tooth. The 

 upper margin of the palm of the larger chela of the male 

 is simply obtuse, not flattened as in the dutch species; 



Note» from the Leyden IMuseum, Vol. XIV. 



