CARCINOLOGICAL STUDIES. 101 



convex and smooth. This species is also characterized by 

 the yellowish red colour of the fingers. 



The two largest specimens have the following dimensions : 



Distance between the external orbital 



angles lö^/g mm. 157^ mm. 



Length of the cephalothorax . . . 12 V3 » 12 » 



Breadth of the front 9^3 » 9 » 



32, Sesarma bataviana, n. sp. 

 (PI. 6, fig. 12). 



One single male specimen, collected by Mr. J. Semme- 

 link on the seashore of Batavia. 



This species which is positively different from Ses. qua- 

 drata Fabr., Ses. picta de Haan and Ses. erythrodactyla Hess, 

 may perhaps prove to be identical with Ses. Melissa de Man, 

 which inhabits the Bay of Bengal , off the coast of Tenasserim. 

 But as I have no typical specimen of the Mergui species 

 before me, I cannot decide this question. 



Sesarma hataviana belongs to that section of the genus , 

 in which the lateral margins are entire and in which the 

 upper surface of the palm in the male is provided with 

 parallel pectinated ridges. In comparing our specimen with 

 the figure of Sesarma Melissa , which 1 have published in 

 my Report on the Crustacea of the Mergui Archipelago , 

 I hardly find any difference. The proportion of the distance 

 between the external orbital angles and the length is the 

 same in both species , but the front is a little broader in 

 Ses. Melissa and in Ses. erythrodactyla. The upper surface 

 presents the same interregional grooves as in the Mergui 

 species ; small tufts of short hair are scattered on it , 

 especially on the postfrontal lobes. The front is a little 

 broader than half the distance between the external 

 orbital angles ; the four subequal postfrontal lobes are 

 •but little prominent, and project less forward than the in- 

 ferior margin of the front. 



The inferior margin is, as in Ses. Melissa, rather 

 Notes from the Leyden IMuseuxxi, Vol. XJLI. 



