972 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. 



cc Second segment of first foot normal, Imt 1 seta. Two sjiines on first 

 maxillaiy process. 

 (/ Spines of maxillary process plainly tootlied. 



e Length, 1.8 mm. or more. Two sette on first segment of first foot. 



irerpeiuci/pris, G. 

 ee Length, 1.0 mm. or less. One seta on first segment of firstfoot. 



Microcf/prix, 7. 



(hi Spines of maxillary process not tootlied I'rionoctjprk, 8. 



««a Natatory setai reaching beyond end claws, or approximately to tips of end 

 claws. Second foot with a beak-like end-segment and a claw. 



Subfamily Cypridin/E, III. 

 h Two eyes. Natatory setfe reaching beyond end cla^\•s. Shell thick and 



strong Cnifrori/jiris, 9. 



bb No eyes, unless rudimentary. 



<• Testes, if present, originating in anterior part of shell, and anteriorly in form 

 of concentric circles or half-circles. 

 d Testes in form of concentric half-circles, anteriorly. Shell small, not 



more than 0.6 mm or 0.8 mm. in length Cypridella, 10. 



dd Testes in form of concentric circles, anteriorly. Shell more than 0.8 mm. 

 in length. 

 e Shell tumid and excessively hairy. Fin-ca normal, slender, no more 



than one-half length of shell Spirocypris, 11. 



ee Shell, as seen from side, narrow, oblong, and smooth. Furca excessively 



develoi^ed, more than one-half length of shell Cypricercas, 17. 



ddd Males unknown. Furca with 2 long terminal sette in place of the 

 usual claws; also usually a short dorsal one. Ovary spirally wound. 



Cypreita, 12. 

 cc Testes, if present, not originating in the anterior i)art of shell, and usually 

 not in circles or half-circles. 

 d Right shell prominently armed jvitli a dorsal, longitudinal, ridge-like 

 process. 

 e Dorsal process, with thorn-like projections at both extremities. Testes 

 appearing as 8 concentric half-circles in posterior part of shell. 



Strandenia, 13. 

 ee Dorsal process, with a thorn-like projection at posterior part only. 



Furca excessively large Acanthocypris, 14. 



dd Shell comparatively smooth, at least no dorsal ridge-like process -present. 

 e Furcal dorsal seta rudimentary or absent. Males present. 



tSteiiocypris, 15. 

 ee Furcal dorsal seta plainly present. 

 / First foot 4-segmented, third and fourth segments united. Shell 



unusually broad. Furca and its claws smooth EuryciijiriK, 16. 



ff First foot not 4-segmented, usually five. Furca usually normal. 



Propagation sexual or asexual Oypri>i, 1 8. 



y Furca normal. 



h Length, .3.00 mm. to 3.50 mm. Sexual. .Subgenus .!////>// /r//y;n'.s, 5. 

 /(/( Length less than 3 nnn. 

 i Parthenogenetic. Valves with or without tubercles. 



Subgenus Cypris, 1. 

 u Sexual. Right valve with marginal tubercles. 



Subgenus Cyprinotus, 2. 

 m Sexual. J^eft valve with marginal tubercles. 



Subgenus Helerorypris, 3. 



