184 Records of the Indian Museum. [Vol. XXIV, 



females. The numbers are unfortunately low but there are numer- 

 ous detached legs of type a in the Manaar collection. 



Type b is most commonly associated with tj'pe c ; the com- 

 bination occurs in both collections and the specimens are often 

 ovigerous. From the Andamans there are two examples of bb, 

 both females, and from the Gulf of Manaar a few bd, all males. 



I^egs of type c, when not combined with b, are associated 

 with d or with another limb of type c. The combination cc ap- 

 pears only in the Andaman collection, where it is very abundant 

 in males and young females ; cd is found in the Manaar collection 

 in one male and three ovigerous females. 



The combination dd is found only in two males from the Gulf 

 of Manaar. 



Although the specimens on which these observations are 

 based are numerous, any speculations on the significance of this 

 remarkable diversity in the form of the legs would at present be 

 unprofitable. Further large collections of adults are necessary to. 

 provide more accurate data and valuable clues may be expected 

 from field observations and from a knowledge of the relations 

 that exist between the prawn and its hosts I will only remark 

 here that I regard it as almost certain that legs of type c in course 

 of growth reach type b and that it is not improbable that type b 

 may develop into type a. 



One point remains to be meutioned — the very curious differ- 

 ences between the two collections of specimens. The combina- 

 tion cc, to which the majority of the Andaman specimens belong, 

 is not represented in the Manaar series, while type d, found in a 

 large proportion of specimens from the latter locality, occurs only 

 in one individual (in the combination ad) from the Andamans. 

 Had it not been for this last specimen I should have been doubt- 

 ful whether the Andaman form did not belong to a separate race 

 or subspecies. On- the information available I am satisfied that 

 all are properly attributed to a single species. The only difference 

 between the two sets of specimens lies in the types of second 

 peraeopod which are combined to form a pair. This may be 

 concerned with the different hosts on which the two series were 

 found and it will be noticed that all four types of leg occur in 

 both collections. 



Periclimenes (Ancylocaris) potina Nobili. 



1905. Periclimenes potina, Nobili, Bull. Mus. Paris XI, p. 159. 



1906. Periclimenes potina, Nobili, Bull. sci. France Belgique XL, p. 



44, pi. iii, fig. 8. 



This species appears to be related to P. diversipes but, ac- 

 cording to Nobili's description, is distinguished by the form of the 

 rostrum and the proportions of the segments of the second 

 peraeopod. The upper portion of the rostrum is not strongly 

 arched, the posterior dorsal tooth is not situated on the carapace 

 and the single tooth on the lower border is in advance of the fore- 

 most on the upper border. The carpus of the second peraeopod 



