Crustacea Decapoda and Stomatopoda. 



285 



The localities from which specimens have been examined have already been 

 enumerated. The range of the species so far as known is Peninsular India, Ivower 

 Siam, Sumatra, Flores and Celebes. 



Caridina gracillima, Manchester. 



1901. Caridina gyacillima, lyaachester, Proc. Zool. Soc. London, p. 560, pi. XXXIV, fig. i. 

 1905. Caridina gracillima. Bouvier, Bull. sci. France Belgique, XXXIX, p. 72. 

 1913. Caridina gracillima, Bouvier, Trans. Linn. Soc, Zool. (2), XV, p. 463. 



As Lanchester has pointed out this form is very closely related to C. gracilirostris . 

 it may indeed be no more than a well marked local race of that species. The principal 

 distinctions between the two are as follows : — 



C. gracillima, lyanchester. 



Rostrum shorter, usually not more 

 than 1 1 times length of carapace. 



Ventral teeth of rostrum less numer- 

 ous, usually not more than 20. 



Outer uropod with 6 to 8 movable 

 spinules. 



Eggs larger, from 0-65 to 070 mm. in 

 length. 



Size smaller ; total length not exceed- 



C. gracilirostris, de Man. 



Rostrum longer, usually more than ih 

 times length of carapace. 



Ventral teeth of rostrum more numer- 

 ous, usually more than 20. 



Outer uropod with 8 to 11 movable 

 spinules. 



Eggs smaller, from 033 to 0-52 mm. in 

 length. 



Size larger ; total length up to 38 mm. 



mg 25 mm. 



The differences noted by lyanchester in regard to the proportionate lengths of the 

 first two peraeopods and the spinulation of the telson break down on actual comparison 

 of specimens. 



In fifty specimens the number of dorsal teeth ' on the proximal part of the rostrum 

 varies from 5 to 10. In forty-nine specimens there is a single subapical dorsal tooth 

 and in one specimen two such teeth. The ventral teeth vary from 13 to 22 (usually 

 14 to 20). 



The antennal scale is from 3-|- to nearly 4 times as long as broad. The peraeopods 

 agree almost precisely with those of the allied species. The dactylus of the third 

 bears from 6 to g teeth and that of the fifth from 30 to 47 (52 according to Bouvier). 



According to Dr. Annandale's notes living specimens were transparent, with the 



1 The teeth in these specimens are arranged thus : — 



Dorsal teeth. 

 7 specimens have 5 teeth. 

 6 



7 



Ventral teeth. 



1 specimen has 13 teeth. 

 4 specimens have 14 



2 ,. ,, 15 



15 



I specimen has 22 



