424 CRUSTACEANS OF THE 



roerus-joint. The ischial line on the outer foot-jaws runs 

 near the internal margin and is prolonged till near tlie 

 anterior border of this joint; the merus-joint is quadrate, 

 the slightly arcuate outer margin makes an obtuse angle 

 with the much shorter anterior one. 



The abdomen (Figs. 14^ and lA'-') resembles that oi Fota- 

 mon horneense^ var, hilaris, being quite narrow and with 

 concave lateral margins. The distance between the anterior 

 extremity of the abdominal cavity and the oblique posterior 

 margins of the buccal frame is a little larger than 

 that between the anterior extremity of the ischial line on 

 the outer foot-jaws and its external margin (Fig. 14^). As 

 regards the shape of the abdomen, I refer to the figure 

 and to the measurements. Sternum and abdomen are smooth 

 with rare punctulations. 



The right chelipede (Fig. 14/) is much larger than the 

 left. The arm is short, its upper margin without a tooth 

 at the distal end and with short transverse rugosities on 

 its outer surface ; the lower surface is smooth , without a 

 tubercle near the carpal articulation and with rather sharp 

 margius that are beset with acute granules. The carpus 

 is covered with small rugosities and its inner margin shows 

 a row of small acute tubercles; there is a short, acute, 

 slightly compressed spine at the inner angle. The larg*er 

 chela is stout, almost as long as the cephalothorax is broad 

 and the fingers, in contact throughout their length, are 

 just as long as the palm. The palm is very slightly higher 

 than long, a few very small granules, that are not at 

 all prominent, are scattered on the rounded upper mai-gin 

 of the palm, a few also on the very convex outer surface 

 near the carpal articulation and on the rounded lower 

 margin, but the greater part of the outer surface is quite 

 smooth, even not punctate. The fingers are together less 

 high than the palm, so that the lower margin of the index 

 is not placed in the same horizontal line as the arcuate 

 lower margin of the palm. The outer surface of the some- 

 what compressed immobile finger is very slightly convex, 



Notes from the Ley den Museum, Vol. XXI. 



