106 



Remarks. This genus was established in the year 1889 by Brady and 

 Norman, to include the Cypris gibba of Ramdohr, and has been admitted by 

 all subsequent authors. Several additional species of this genus have in recent 

 times been recorded both from Europe and from more southern latitudes; but 

 some of these are so closely related, both as to the ex'ernal appearance and 

 to the structural details, that their specific validity has been often questioned. 

 2 such closely allied species will be described below. 



35. llyocypris biplicata (Koch). 



(PI. XLIX). 



Cypris biplicata, Koch, Deutschlands Crustaceen, H. 21, PI. XVI. 

 Syn: llyocypris gibba van. (auctorum). 



Specific Characters. Female. Shell rather compressed, seen laterally, 

 oval quadrangular in shape, somewhat higher in fiont than behind, greatest 

 height in the ocular region and slightly exceeding half the length, dorsal 

 margin nearly straight and a little sloping behind, forming a somewhat pro- 

 minent convexity in the ocular region and joining the hind edge by a well- 

 marked angular bend, ventral margin rather deeply sinuated in the middle, 

 anterior extremity broadly rounded off, posterior obtusely blunted; seen 

 dorsally, narrow oblong in outline, with the greatest width scarcely exceeding 

 2 /o of the length and occurring behind the middle, anterior extremity obtusely 

 pointed, posterior rounded off. Valves subequal, with the 2 vertical folds in 

 front very conspicuous, but without any traces of projecting lateral protuberances, 

 anterior edges very finely denticulated in their whole extent, posterior edges 

 likewise denticulate, but with the denticles less densely crowded, both extremities 

 moreover rather densely clothed with fine hairs. Surface of shell coarsely 

 granular, with densely set small rounded pits. Anterior antennae with the 

 terminal part about the length of the basal one, joints gradually diminishing 

 in size, setaz very long and slender. Posterior antennae with the penultimate 

 joint much shorter than the preceding joint, natatory setae much elongated, 

 extending far beyond the tips of the claws. Posterior legs with the shorter of 

 the 2 apical setae about half the length of the other, which equals the outer 

 seta in size. Caudal rami slightly curved and gradually attenuated, apical 

 claws rather thin, the distal one about half the length of the ramus, dors 

 seta attached at about the outer Vs of the ramus. 



Male of smaller size than female, but resembling it in the general sliaj 

 of the shell. Prehensile palps of maxillipeds with the propodus not at, all 



