2o8 Records of the Indian Museum. • [Vol. XXIV, 



The last three pairs of peraeopods (textfig. 56^) are long and 

 slender; the fifth pair reaches to or a little bej^ond the end of 

 the antennal scale. The merus of the third pair is about 15 to 16 

 times as long as broad in adults. The propodus bears some slen- 

 der spinules on its posterior edge and is from 2*7 to 36 times as 

 long as the dactyl us, proportionately longest in large males. The 

 dactylus is simple and curved, with a few setae on the middle 

 of its anterior margin ; it is from 75 to 8 times as long as its basal 

 breadth. 



The sixth abdominal somite is about 17 times the length of 

 the fifth. In the arrangement of the spines the telson resembles 

 that of P. agag. 



A large male is about 19 mm. in length. 



Periclimenes andamanensis agrees with P. proximus and differs 

 from P. agag in the comparatively stout first and second legs and 

 in the greater length of the chela of the second legs, as compared 

 with the carpus, in adults of both sexes. From both species it is 

 distinguished by the presence of the carpal spine. It also differs 

 from P. proximus in the greater number of upper rostral teeth, in 

 the proportionate lengths of merus, carpus and chela in the second 

 leg of the adult male and in the rather more slender legs of the 

 last three pairs. Other minor differences will be found on com- 

 parison of the two descriptions given above. 



C 380-1/ 1. Port Blair, Andamans, S. Kemp, Feb., 1915 ; Many. 



4-8 fms. Feb., March, 1921. 



The specimens were found in Ross Channel in company with 

 P. agag and P. proximus. The types bear the number C 380/1. 



Certain additional specimens obtained on muddy ground at 

 the inner end of Port Blair are tentatively referred to P. andaman- 

 ensis, but differ in certain characters which will perhaps prove to 

 possess at least varietal value. Of the nine specimens eight are 

 females and one a young male. 



The only points in which these specimens differ from the above 

 description are as follows : — 



The rostrum is less shallow and bears as a rule 9 dorsal teeth 

 and 3 ventral. 1 The ovigerous females are larger than any typical 

 P. andamanensis that I have seen, with the carpus of the second 

 peraeopods decidedly stouter, from 5*5 to 6 times as long as its 

 distal breadth. The chela also is longer in relation to the carpus, 

 about 1*8 times its length. In the last three legs the dactylus is 

 considerably longer than in typical specimens. In large females 

 the propodus of the third pair is only 225 times and in the young 

 male only twice the length of the dactylus. The dactylus is also 

 rather more slender from 8 to 9 times as long as its basal breadth 

 in females, 11 times in the young male. 



1 Of eight specimens one has 8 dorsal teeth, six have 9 and one has 1 1 

 specimens have 3 ventral teeth and one has 4. 



