40 G. o. SARS. M.-N. KL 



chitinous stripe (see fig. i e). When inllected within the shell, the rami 

 extend with their claws nearly to the oral region, and, including the 

 claws, thev considerably exceed in length half the shell. In form they 

 are (see fig. i d) linear, or very slightly narrowed distally, exhibiting a 

 very faint sigmoid fiexure. They terminate each, as in the genus Cypris, 

 with 2 strong, and but slightly curved claws, the outer of which about 

 equals in length Vs '^'^ the ramus. Just in front of it issues from the tip 

 of the ramus a slender bristle, and a similar bristle originates from the 

 dorsal edge at a short distance from the other claw. Above this bristle 

 the dorsal etlge is minutely denticutaled for about ^/a of its length. The 

 rami are highly mobile, admitting of being thrown out of the shell and 

 extended behind in the longitudinal axis of the latter. 



Of the inner organs, both the coecal appendages of the intestine and the 

 ovarial tubes, exhibit characteristic differences from those parts in other 

 Cyprididae. The first named appendages (see fig. i a, i c) are unusually 

 short, not even extending midway to the hind extremity of the shell. 

 On the other hand, the ovarial tubes are ver}- much elongated, with the 

 terminal part doubled upon the proximal one (see fig. i a\ 



The colour is generally a golden yellow, clouded dorsallv, behind 

 the ocular region, with light green. The ovarial eggs shine through the 

 shell with a yellow orange colour. 



The adult male (fig. i c) is somewhat smaller than the female, 

 scarcely exceeding in length 1,3:; mm., and does not differ essentiall}- in 

 the form of the shell. It is however easily recognizable by the spermatic 

 ducts being rather distincdy traced through the shell, and partly also by a 

 somewhat darker, ochraceous colour. 



As to the arrangement of the spermatic ducts, they show this pecu- 

 liarity, that the anterior ones are bent downwards and coiled up in a 

 dense whorl within the anterior part of each valve (see fig. i c & i e), 

 instead of, as in most other Cyprididae, extending along the edges of 

 the anterior extremity. 



The mucous glands are rather small and narrow, and are only faintly 

 traced through the walls of the posterior part of the bodv, being concealed by 

 the strong muscles passing on each side to the caudal rami (see fig. i e). 



The sexual characters are, otherwise, the usual ones, the palps of the 

 2nd pair of maxillae being modified to strongly hooked grasping organs, 

 which are somewhat unecjual on each side (comp. fig. i e and i g). The 

 copulative apparatus is also normally constructed, consisting, as usual, 

 of 2 symetrical halves (fig. i h; of chitinous consistency, and containing 

 each the up-curled end of the efferent duct of the testes, 



