DAPHNIOIDEA. 1271 



Plate 89, fig. 3 a, dorsal view, enlarged ; b, side view ; c, ventral 

 view ; d, antenna; e, one of the natatory legs. 



East Indies, at the eastern entrance of the Straits of Sunda. Col- 

 lected, March 5, 1842. 



This species is near the preceding, and at first appeared to be iden- 

 tical with it. But the dorsal abdominal setae are more than twice the 

 length in that species, while the stylets at the extremity of the abdo- 

 men are shorter in proportion, being a little shorter than the abdomen. 

 These stylets have an appearance of a suture near base, and there are 

 two very short setae on the outer side at this suture or pseudo-articula- 

 tion. The front in an upper view is straight truncate, or scarcely tri- 

 angular. The anterior margin of the shell below the head is much 

 longer, and rounds with a much broader curve into the inferior margin. 

 It forms an acute angle with the posterior side of the rostrum, while in 

 our drawing of the P. avirostris there is a short neck below, separating 

 the two. The concavity at the middle of the posterior margin of the 

 shell is quite shallow, and the acute posterior angles of the shell are 

 less prolonged as seen in a dorsal view. 



The setae of the antennae are a little longer than the branch ; the 

 second joint of the branches is about one-third as long as the first. 

 The mouth consists of a pair of stout mandibles, situated transversely, 

 with broad dentate extremities. No palpus was detected. Posterior 

 to the mandibles, there is a pair of slender maxillae, having at apex a 

 few short spines. 



The dorsal cavity contained three large embryos. 



Penilia orientalis, Dana, Proc. Amer. Acad. Sci. ; Boston, ii. 47. 



Genus DAPHNIA, Muller. 



We separate from this genus the species having the shell reticulate, 

 with hexagonal or pentagonal cells. 



Daphnia australiensis. 

 Valde tumida, paulo obhnga, eapite per constrictionem vix discrete, pone 



