102 CARCINOLOGICAL STUDIES. 



profoundly and widely eraarginate in the middle, 

 and presents therefore on each side of this median sinus 

 a rather prominent, rounded lobe; the inferior frontal 

 margin of Ses. erythrodactyla, however, is scarcely emargi- 

 nate and the lateral lobes are much less prominent. As 

 in Ses. Melissa , the orbits are rather large , the external 

 orbital angles acute and prominent, and the lateral mar- 

 gins are slightly concave ; the lateral sides of the upper 

 surface are wrinkled by several oblique elevated lines. 



The anterior legs are of equal size and rather large. 

 The upper margin of the arms terminates in an acute 

 tooth, as in Ses. Melissa; in Ses. erythrodactyla this 

 tooth does not exist, the upper margin terminating, before 

 the distal end, in an obtuse angle. As in the Mergui spe- 

 cies, the anterior margin is also armed with an acute 

 spine. The upper surface of the wrist is covered with 

 minutely granulated transverse lines and unarmed at its 

 internal angle. The hands (fig. 12) are characteristic. They 

 are of equal size and a little more than once and a half 

 as long as high , the palm about as long as high , and the 

 fingers horizontally as long as the palm. The inner margin 

 of the upper surface of the palm rises a little towards its 

 distal end ; the upper surface presents two parallel 

 pectinated ridges, of which the anterior one consists of 17 

 horny teeth, the posterior one of 13. The pectinate ridges 

 have a different direction in this species and in Ses. ery- 

 throdactyla'. in the latter they run very obliquely, close 

 to and parallel with the oblique posterior 

 margin of the upper surface, the two ridges 

 being as far distant from one another as the 

 posterior ridge from the posterior margin; in 

 Ses. bataviana, however, the ridges do not run pa- 

 rallel with the oblique posterior margin of 

 the upper surface, but they form right angles 

 with the short raised inner margin of it, thus 

 leaving a triangular space between the pos- 

 terior ridge and the posterior margin. I suppose, 



Notes from the Leyden. ]Museuin , "Vol. X!1I. 



