CARCINOLÜGICAL STUDIES. '261 



bed t,o its small size, as the cephalothorax of Ses. sulcata 

 attains to a breadth of 3i mm. 



Ses. crassipes is probably likewise different , for the ce- 

 phalothorax of this species seems to be a little less en- 

 larged , the upper surface rugose , the frontal margin pro- 

 foundly emarginate and the outer surface of the hands 

 covered with very small scales („minutissime squame"). 



14. Caridina japonica, n. sp. 

 (Figs. 7 and 8). 



Six specimens from Kagar, Hayagana , Japan. 



These specimens, which were kindly presented to me 

 with some other species from Japan by Dr. J. Anderson , 

 are nearly all of the same size and 32 or 33 mm. long 

 from the tip of the rostrum to the end of the telson. It 

 is to Caridina Weheri de Man, from Celebes and Flores , 

 that this species is most closely allied. The rostrum is 

 small and closely resembles that of Car. Weheri:, it is 

 somewhat directed downwards and scarcely 

 reaches to the middle of the penultimate joint 

 of the upper antennae, sometimes even only to the 

 distal end of the first joint. The upper margin is straight 

 or very slightly concave and the point of the rostrum very 

 acute; both margins are dentate. The formulae of these 

 teeth for the six specimens are the following: If, ffi ||, 

 T¥» Vi ^i' The number of teeth on the upper margin 

 therefore varies from 15 — 22, those of the lower margin 

 from 10 — 18, when the two last specimens are considered 

 as making an exception. The teeth of the upper margin 

 are comparatively a little smaller than those of Car. We- 

 heri and generally decrease somewhat in size towards the 

 tip; like in that species all the teeth are standing 

 on the rostrum itself, none of them on the ce- 

 phalothorax, and the foremost tooth stands 

 at a small distance from the tip. The teeth of the 

 lower margin are smaller than those of the upper and 

 mostly increase slightly in length anteriorly. 



r^otes from ttie I^eyden Museum, Vol. XIV". 



