FRESHWATER ENTOMOSTRACA FROM SOUTH AFRICA. 461 



Genus Hyalocypris gen. nov. 



Shell oblong, compressed, slender and translucent. An- 

 tennas as in Gyp 1" is. Mandible-palp bears a small 6-setose 

 branchial plate; mouth, labrum and oesophageal opening 

 without serratures or teeth ; first maxillar palp complex, 

 profusely setiferous, and bearing also a large bulb-shaped, 

 tapering appendage which terminates in a long seta (PI. 

 XXXIII, fig. 4) ; the feet of the second pair have a very long 

 terminal claw, and at the distal end of the basal joint a large 

 spherical vesicle which bears a small lateral denticle. 



The marked peculiarities of the mouth-organs, together 

 with the characteristic vesiculiform appendages of the second 

 pair of feet, seem to sepai'ate the following species very dis- 

 tinctly from those of any hitherto described genus. 



Hyalocypris africana sp. nov. PL XXXIII, figs. 1-6. 

 Shell, seen laterally, oblong -ovate (fig. 1), somewhat 

 narrower in front than behind; greatest height situated in 

 the middle and equal to about half the length, anterior 

 extremity evenly rounded, posterior wider and more flattened, 

 dorsal margin forming a gently arcuate curve, ventral almost 

 straight ; seen from above (fig. 2) the outline is compressed, 

 oblong, almost lozenge-shaped, widest in the middle, the 

 width equal to one-third of the length, tapering to the 

 extremities, the posterior rather obtuse, anterior more 

 pointed ; shell very thin and delicate, hyaline, surface smooth, 

 very finely hairy towards the margins. Length 1*1 mm. 

 The autennules and antennge are normal in structure, the 

 fascicle of swimming setse extending well beyond the apices 

 of the antennal claws ; mandibles stout, mandibular palp short 

 and stout, the last joint very small ; branchial plate small, 

 bearing six setas ; first and second pairs of maxillaB as usual 

 except that the first pair (fig. 4) bear a larger pyriform 

 marginal plate which ends in a rigid seta; mouth aperture 

 and oesophagus very feeV)ly developed ; labrum devoid of 

 serratures, but produced at each side into a stout bifid pro- 

 cess (fig. 3) ; first pair of feet (fig. 5) bearing an extremely 



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