The Fresh-water Entomostraca of Cape Province. 317 



14. CERIODAPHNIA QUADRANGULA (MULLER), var. 

 (Plate XXXIII, figs. 3, 3, 6.) 



Daphnia quadrangula, O. Fr. Miiller. Entomostraca, 1785, p. ii, 

 pi. xiii, figs. 3 and 4. 



Specific Characters Female. Carapace, seen laterally, rounded 

 quadrangular in outline, with the posterior protuberance distinctly 

 produced and issuing far above the axis of the body. Head rather 

 procumbent, with the frontal part evenly rounded off, without any 

 angle behind. Reticulation of shell coarser than in the two preceding 

 species ; free edges of valves minutely denticulate, the denticles being 

 also continued on the hind part of the dorsal margin. Eye of moderate 

 size. Antenuulae somewhat more produced than in the two preceding- 

 species. Tail-piece comparatively short and stout, with the posterior 

 edge scarcely sinuated ; anal denticles of uniform size, and about eight 

 on each side ; apical claws perfectly smooth. 



Body somewhat less pellucid than in C. reticulata, with a yellowish- 

 grey tinge. 



Length of shell reaching 0'9 mm. 



Remarks. This form also I have been induced to identify with 

 a well-known European species, viz., C. quadrangulata (Miiller), 

 though it differs somewhat from typical specimens of that species 

 in the coarser reticulation of the shell and the distinctly denticulate 

 edges of the valves. Otherwise I have, however, failed to detect any 

 reliable difference to distinguish it specifically. 



Occurrence. Some specimens of this form were reared in one of 

 my acpuaria prepared with mud from the Cape Flats kindly sent to me 

 by Dr. Purcell. 



Distribution. Throughout Europe, Central Asia, Greenland. 



15. CERIODAPHNIA DUBIA, Richard. 

 (Plate XXXIV, figs. 1, 1 a, 6.) 



Ceriodaphnia dubia, Richard. Entomostraces recueillis dans le lac 

 Joba, Sumatra. Ann Mus. Gen. xxxiv, 1895, p. 570, text-figs. 6-8. 



Specific Characters Female. Carapace, seen laterally, oval in out- 

 line, with the posterior protuberance rather short and issuing some- 

 what above the axis of the body. Head less procumbent than in 

 C. quadrangula, with the frontal part narrowly rounded and distinctly 

 angular behind. Shell very thin, with the reticulation rather faintly 

 marked ; edges of valves smooth. Eye comparatively large. Anteu- 

 uulae about as in C. reticulata. Tail-piece with the posterior edge 



