CARCINOLOGICAL STUDIES. 249 



Length of the meropodites of the last pair of 



legs I6V2 ^i^"^' 



Breadth of the meropodites of the last pair of 



legs 9 » 



The lateral margins of the cephalothorax converge 

 slightly backwards. The chelipedes are provided with a 

 finely denticulate ridge on the upper margin of the palm , 

 the outer surface of which is smooth. The meropodites of 

 the ambulatory legs are much enlarged and the propodi- 

 tes are scarcely shorter than the dactylopodites. 



10. Sesarma recta Randall. 

 (Fig. 4). 



Sesarma recta ^ Randall, in: Journal of the Academy of Nat. 

 Sciences of Philadelphia, Vol. VIII, Part 1, 1839, p. 123. 



Seven specimens , three males and four females , two of 

 which are provided with eggs , were collected in Surinam 

 by Dr. H. ten Kate. 



I refer them to Ses. recta Rand. — a species said to 

 be found in Surinam — with some doubt however, be- 

 cause the literature on the other West-Indian Decapoda is 

 only partly at my disposal. 



This species belongs to that section of the genus , in 

 which the lateral margins of the cephalothorax are entire, 

 without an epibranchial tooth behind the ex- 

 ternal orbital angles and in which the hands of 

 the male are not provided with pectinated rid- 

 ges on the upper margin of the palm. It may at 

 first sight be recognized by the singular enlarge- 

 ment of the mobile finger of the male at its 

 base. 



Sesarma recta presents a remarkable resemblance , as 

 regards its general form and appearance , with Ses. quadrata 

 Fabr. from which it differs at first sight by the absence 

 of pectinated ridges on the hands of the male. 



The cephalothorax has a quadrate form and appears but 



Notes from the Leyden M!useuxn, A^'ol. XIV. 



