Gen. 1. Cypridina, M. Edwards, 1840. 



Generic Characters. Sexual dimorphism rather slight. Shell moderately 

 tumid and of a more or less oval shape, with the surface smooth and almosl 

 quite devoid of hairs; frontal incisure of valves rather deep and occurring 

 nearly in the middle of the anterior extremity; rostral part, as a rule, nol 

 much prominent and curved downwards. Eyes well developed in both sexes 

 but larger in male than in female. Frontal tentacle short, clavate. Anterioi 

 antennae 7- articulate, and of nearly same structure in the two sexes. Posterioi 

 antennae with the inner ramus in most cases not transformed in male. Man- 

 dibles with the masticatory process small, conical in shape, and densely hairy 

 palp with the penultimate joint long and narrow, being densely clothed ir 

 front with coarse setae, apical claws very short. Anterior lip forming in from 

 a compressed somewhat securiform expansion finely crenulated at the edge 

 and having moreover 2 more or less distinctly defined lateral lappets. Maxilla 

 with 3 well defined masticatory lobes inside the thickish basal part, palp rathei 

 strong biarticulate, and provided outside with a thin deflexed lamella terminating 

 in 3 finely ciliated setae, and apparently constituting the exopodite, distal joint of the 

 palp small, but armed with several strong diverging spines. Anterior maxillipeds 

 of a very compact and complicated structure, with the basal part broad and 

 flattened carrying on the one side the large vibratory plate, on the opposite 

 (inner) side 3 comparatively small subequal masticatory lobes, these lobes being 

 followed by 2 somewhat similar, but much stronger incurved lobes, which to- 

 gether with the adjoining part of the limb may more properly represent tht 

 endopodite, the distal lobe being clothed with numerous strong partly pectinate 

 setae, the proximal one with a row of short stout claws denticulated along the 

 one edge, the remaining part of the limb apparently represents the exopodite 

 and is of a much more delicate structure, exhibiting a short proximal join 

 which is produced on each side to;a setiferous lappet, the 2 lappets embracing, 

 as it were, the base of the succeeding quadrangular joint, to the outer cornei 

 of which in some cases a very small apical joint is added 1 ). Posterior max- 

 illipeds with 3 or 4 masticatory lobes, the outermost of which, together with 

 the adjoining part, may perhaps represent the endopodite, terminal lamella 

 (exopodite) richly fringed with ciliated setae, those issuing from the posterioi 

 corner being the largest. Last pair of limbs exhibiting the characteristic structure 



*) The 'interpretation here given somewhat differs from that set forth by Dr. Skogsberg 

 who described the whole outer part of the limb as the exopodite. 



