1920.] S. Kemp : Notes on Crustacea Decapoda. 143 



in the single ovigerous female, but appear to have been about 0*85 

 by 0'7 mm. in longer and shorter diameter. In life the specimens 

 were colourless and semitransparent ; the eggs borne bj^ the female 

 were green. 



Discias exul differs from Miss Rathbun's D. serrifer in a 

 number of particulars. D. serrifer is a much larger species, 15 

 mm. in length, with a punctate carapace and with the antennal 

 scale projecting further beyond the end of the antennular peduncle. 

 The palmar portion of the chela of the first peraeopods is less than 

 twice as long as broad in D. serrifer, but more than twice in D. 

 exul and whereas the postero-inferior angles of the fifth and sixth 

 abdominal pleura are rounded in the latter species, the}- are 

 subacute in the former. In the tail-fan there are striking differ- 

 ences. The telson bears ten or twelve terminal spines in D. 

 serrifer and there is a series of ten to twelve teeth on the external 

 margin of the outer uropod ; in D, exul there are only eight spines 

 at the apex of the telson and the margin of the outer uropod is 

 unarmed. 



The five specimens of D. exul were found on a yellow sponge ; 

 they were obtained at low water on March ist, 1915, at Port Blair 

 in the Andaman Is., on the reef at the N. end of Ross I. 



