172 DE. J. &. DE MAN ON THE PODOPHTHALMOUS 



Sesarma picta may be easily distinguished from Sesarma 

 quadrata, Fabr. { = affinis, de 'Hdid^n^ungulata, M.-Bdvv.), from S. 

 aspera, Heller, and I'rom 8. erythrodactyla, Hess, by its narrow 

 front, whicb is exactly half as broad as the distance between the 

 external orbital angles. The ambulatory legs of S. picta, de 

 Haan, are moreover of a more slender form than those of S. 

 qua drat a. 



Sesarma picta has been found in Japan, and the Leyden 

 Museum possesses a specimen from Macassar, Celebes ; it is 

 therefore probable that this species will be found to occur in the 

 Malayan Archipelago. 



95. Sesarma Andbesoni, n. sp. (PI. XII. figs. 1-4.) 



ISTineteen specimens (8 J , 11 $ ) of this most interesting species 

 were " found at low water, in the deej) but narrow burrows of 

 dead Novaculina sp., on the banks of the Tenasserim river, at 

 Minthantoung." 



The numerous species of the genus Sesarma nearly all agree 

 with one another, so far as I am aware, in one character, namely, 

 that the posterior margins of the meropodites of the ambulatory 

 legs are entire, and never armed with the acute teeth which are 

 characteristic of the more typical G-rapsidae. In only a single 

 species, viz. the Japanese Sesarma vestita, Stiiiipson, are the mero- 

 podites of the ambulatory legs described as being denticulate at 

 the external angle of their posterior margin. 



Sesarma Andersoni appears to be allied to S. vestita, but may 

 be distinguished from it at first sight by its much more enlarged 

 carapace, which has a glabrous and shining upper surface, and 

 by many other characters. S. vestlta and this new species are 

 among the smallest representatives of this interesting genus, the 

 cephalothoras being little more than one centimetre broad. 



The cephalothorax is enlarged, being much broader than long ; 

 the proportion of the distance between the external orbital angles 

 to the length of the carapace is as 13 : 9|. The rather depressed 

 upper surface is marked with the ordinary interregional grooves 

 and IS quite glabrous, smooth, and bright, though minutely 

 punctate, when seen under a magnifying-glass. The front is 

 rather broad ; measured between the eye-peduncles, its breadth 

 slightly exceeds half the distance between the external orbital 

 angles, the proportion being as 7_f : 13. The front is vertically 

 deflexed, its anterior margin is nearly straight, not at all 



