28 R. (il'RXEN' : I ndinii Frcslrn'afcr Entomostraca. [\'()L. [, 



Numerous females of this species were found in two collections 

 made in Calcutta (Nos. 12, 13), but it was only after prolonged 

 search that I was able to find a single male. This is all the more 

 remarkable inasmuch as most of the females bore long, slender 

 spermatophores. 



21. Diaptonms contortus, n. sp. 



The form of the body in both sexes is slender, tapering con- 

 siderably in front, and with the greatest breadth somewhat behind 

 the middle (fig. 9) In the female the division between the 

 fourth and fifth segments of the thorax is marked by a ring of fine 

 denticles. In the male the ring is incomplete dorsally. The 

 fifth segment is scarcely at all expanded laterally and is armed on 

 either side with two teeth, those on the left being larger than those 

 on the right. The first segment of the abdomen is very short, 

 scarcely longer than the second, and bears a long and very stout 

 spine on the left and a shorter and smaller one on the right. In 

 the male the first segment bears a long, slender spine on the right 

 side. The antennae of the female reach, when reflexed, consider- 

 ably beyond the end of the f ureal setse. In the male the antepen- 

 ultimate joint of the prehensile antenna is produced into a short 

 process, recurved at the end, less than half the length of the suc- 

 ceeding joint The last joint has no process. 



In the last pair of legs of the female the basal joint bears a very 

 large, spine-like, cuticular process, which appears to be generally 

 larger on the right leg than on the left (fig. 10). The endopodite 

 reaches nearly to the end of the first joint of the exopodite, and is 

 pointed at the end, with a ring of cilia, but no setse. The second 

 joint of the exopodite bears a very large lateral tooth, at the base 

 of which the vestigial third joint may be detected in the form of a 

 minute tubercle bearing two setse, one long and one short. 



In the male the right leg of the fifth pair is conspicuous 

 for the number and arrangement of the hyaline membranes 

 borne by it. The basal joint bears one pointed process ; the second 

 basal joint bears a large rounded hyaline membrane on its inner 

 face, while the first joint of the exopodite bears two hyaline mem- 

 branes, one of which has a peculiar semi-lunar outline. The endo- 

 podite is slender and cylindrical, longer than the first joint of the 

 exopodite. The second joint of the exopodite bears a large lateral 

 spine rather proximal of the middle. The apical claw is long and 

 much curved, being swollen at the base and peculiarly twisted. 

 In the left leg the terminal joint of the exopodite has a peculiar 

 chela-like shape, owing to the long spine borne by it opposing itself 

 to the very much produced joint itself. 



lycngth of female, i'25 mm. 

 ,, ,, male, I'o mm. 



This species occurs in considerable numbers in several collec- 

 tions both from Calcutta and Chakradharpur (Nos. 7, 8, q, 16, 

 17)- 



