CARCINOLOGICAL STUDIES. 231 



hairy, but are not provided with a tubercular eminence 

 or tooth as in some other species of this genus. The short 

 and quadrate basal joint of the external antennae reaches 

 to the front. The epistorae is smooth and the endostome 

 distinctly ridged on each side. The abdomen of the male 

 seems to be five-jointed, as the third, fourth and fifth 

 segments are probably coalescent, but Hoek figures it 

 (1. c.) as seven-jointed; the penultimate segment is dis- 

 tinctly broader than long. The sternum of the 

 male is somewhat granulated on the anterior segment, 

 near the abdomen , near the maxillipedes and near the ba- 

 sal joint of the chelipedes. 



The chelipedes of the male are very unequal and iu all 

 the specimens before me the right is the larger. The up- 

 per margin seems to be unarmed at the distal end , but 

 presents a strong , acute , somewhat curved tooth in the 

 Mergui species. The under margin is obtusely rounded and 

 the anterior somewhat hairy. The wrist is armed at the 

 internal angle with a scarcely acute tooth and appears 

 somewhat uneven and granular on the upper surface , es- 

 pecially that of the smaller chelipede. The hand of the 

 larger chelipede (fig. l^^) is exactly as long or scarcely 

 shorter than the breadth of the cephalothorax. The palm 

 is about once and a half as long as the fingers , measured 

 horizontally and but little longer than high. As in Heterop. 

 indica , the outer surface of the palm is rather convex and 

 quite smooth; the upper margin, which in the Mergui 

 species was described by me as obtuse, appears remarka- 

 bly flattened in Heterop. tridentata and is separated 

 from the outer surface of the palm by a more or less 

 distinct longitudinal crest , running parallel with the inner 

 border of the upper margin. In some individuals this flat- 

 tened upper margin, sometimes even slightly concave, 

 appears minutely granular, especially along its borders, 

 when seen under a lens. The convex inner surface of the 

 palm is equally smooth. The fingers, which have pointed tips 

 and leave, when closed, a small hiatus between them , are 



Notes from the Leyden iMuseum, Vol. XIV. 



