The Fresh- n;iter EntiH*tr<-" <>/ Gape Province. 



unlike that in female, being much narrower and conically tapered 

 distally, with the end produced in front of the rather small apical 

 claws into a cylindrical appendage containing the terminal part of 

 the vasa deferentia; sub-marginal spines fewer in number and 

 densely crowded below. 



Colour of female more or less bright red, that of male much paler. 



Length of female reaching O86 mm. 



Remarks. This new species is especially characterised by the 

 imperfect development of the eye, which is smaller than in any of the 

 other species known to me. It may also be easily distinguished from 

 the two preceding species by the more produced rostrum and by the 

 shape and armature of the tail-piece. 



Occurrence. Specimens of this form were reared from mud taken 

 in three different localities, viz. Green Point Common, Klipdam, and 

 neighbourhood of Bergvliet. Except in the Klipdam mud, it only 

 occurred very occasionally. 



GEN. 10. ALONA, Baird. 



Remark*. The species of this genus may generally be recognised 

 by the compressed more or less quadrangular shell, the valvular part 

 of which, as a rule, is sculptured with regular longitudinal striae. 

 The genus is very rich in species, and is also well represented in the 

 fauna of Cape Colony, no less than nine different species being dis- 

 tinguished, four of which are apparently new to science. 



29. ALONA AFFINIS (Leydig). 

 (Plate XXXIX, figs. 1, 1 a.) 



Lynceug affinis, Leydig. Naturgeschichte der Daphnideu, I860, 

 p. 223, pi. ix, figs. 68 and 69. 



Syn: Lynceti* quadrangular is, Fischer (not Miiller). 

 Alotia oblonga, P. E. Miiller. 



Specific Characters Female. Shell, seen laterally, oblong oval in 

 outline and somewhat obliquely truncated behind, dorsal margin 

 evenly curved throughout, hind edges of valves slightly arcuate, lower 

 ones * nearly straight. Head only slightly procumbent, with the 

 rostral corner rather prominent and pointing obliquely in front, 

 Surface of valves sculptured with faint, somewhat distant longitudinal 

 striae. Eye of moderate size ; ocellus a little smaller, and about twice 

 as remote from the tip of the rostrum as from the eye. Antennulae 

 not nearly extending as far as the rostrum. Tail-piece rather strongly 



