1922.] S. Kemp: Notes on Crustacea Dccapoda. 285 



eggs and ovary were orange or orange-red. In males the white 

 chromatophores were usually absent and the red less numerous. 



C 436-7 1. Port Blair, Andamans. S. Kemp, March, Thirteen. 



1915 ; Feb., 1921. 

 C -I3S/1. Cherbaniani Reef. ' Investigator,' Oct., Four. 



Laccadives. 1891. 



7421/10. Torres Straits. Brit. Mus. One. 



All the specimens were found in Tridacna. At Port Blair they 

 were obtained on the shores of Aberdeen and North Bay in mol- 

 luscs chiselled out of solid coral rock. The prawn was compara- 

 tively scarce and was found in only a small proportion of shells 

 that were opened. 



C. tridacnae is apparently found only in Tridacna, but in 

 view of Borradaile's statement that C. meleagrinae sometimes oc- 

 curs in this genus of molluscs it is difficult to determine the dis- 

 tribution of the species with accuracy from the numerous pub- 

 lished records. The species is in all probability widely distributed 

 in the Indo-Pacific region. 



Conchodytcs meleagrinae Peters. 



191 7. Conchodytes meleagrinae, Borradaile, Trans. Linn. Soc. (2) 

 Zool. XVII, p. 393. 



The question of the validity of this species and of the charac- 

 ters by which it may be separated from the very closely allied C. 

 tridacnae has been discussed by Borradaile. I have myself seen 

 only four specimens of Conchodytes from Meleagrina and two of 

 these are in bad condition. They differ from C. tridacnae in two 

 of the characters mentioned by Borradaile : the rostrum does not 

 reach the end of the antennal scale and the carpus of the first 

 peraeopod is conspicuously shorter than the merus. The third 

 maxilliped is, however, similar in length to that of the related 

 species and does not nearly reach the end of the scale. 



The specimens also differ from C. tridacnae in the following 

 points : (i) the outer margin of the basal segment of the antennu- 

 lar peduncle terminates acutely; (ii) the ultimate segment of the 

 third maxilliped is a little longer, about equal in length with the 

 penultimate; (iii) the last three peraeopods are rather more slen- 

 der — the merus of the third pair is from 3*2 to 3*5 times and the 

 propodus from 3*5 to 4*3 times as long as wide ; (iv) the dorsal 

 spinules of the telson are proportionately a little longer and the 

 posterior pair is placed further forwards, the distance between 

 the posterior pair and the apex being, in both sexes, slightly 

 more than half the distance which separates the two pairs. 



These characters combined with those derived from the pro- 

 portionate length of the rostrum and the carpus of the first leg are 

 sufficient, if constant, to justify the retention of two distinct 

 species. 



The specimens I have examined are all small, the largest 

 being only 21 mm. in length. 



