DAPHNIOIDEA; J273 



viso bene acuto. Testa apud margines dorsales infero-posticosque et 

 spinam caudalem subtilissim& denticulata. Rami antennarum posti- 

 carum cequi. 



Slender elongate, produced behind into a long spine, which is but 

 little shorter than the body ; head large, not separate, below not 

 produced into a beak, equalling the body in height ; front in side 

 view rounded, in upper view acute. Dorsal and infero-posterior 

 margin minutely denticulate. Branches of the inferior antennae 

 equal. 



Plate 89, fig. 5 a, side view, enlarged ; b, upper view of head, in 

 outline. 



From fresh-water pools, near Sydney, New South Wales. 



The slender body, long aculeate prolongation of the shell behind, 

 and the large non-rostrate head, acute in a dorsal view, are strong 

 characteristics. The dorsal line, from the head to the tip of the 

 caudal elongation, has an uninterrupted gentle concave curvature, and 

 the same bends around the front of the head. The head in profile is 

 convex subtriangular, and the outline is continuous with the outline 

 of the venter, excepting a slight emargination. The height of the 

 body is nearly the same before and behind, and is scarcely greater 

 at middle than elsewhere. 



DapJinia macrura, Dana, Proc. Amer. Acad. Sci., ii. 48. 



Genus CERIODAPHNIA, Dana. 



Corpus fere globosum, capite brevi, instar rostri infra vix productum. 

 Antennas anticae, minutaz (raro etongatm?). Testa cellulis hexagonis 

 vel pentagonis areolaia. 



Body nearly globose, head quite short and not produced into a beak 

 below. Anterior antennas minute (rarely elongate ?) . Shell areo- 

 late, with hexagonal or pentagonal cells. 



This genus includes the Daphnia rotundata and allied species. 



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