1885.] 



CLADOCF.RA. 



29 



4. Moina propinqua, XL sp. 



(Pl. 5, figs. 4, 5; Pl. 6). 



Specific Character. — Female: — General habitus very 

 similar to that of M. brachiata. Head with dorsal margin only 

 slightly concave above the eye, front somewhat projecting and 

 narrowly rounded, ventral margin well-nigh straight. Carapace 

 with dorsal part in gravid specimens often enormously expanded, 

 valves comparatively small, sculptured with distinct transversal 

 flexuous striæ, and fringed along the inferior edges with short 

 setæ. Eye of moderate size. Antennulæ densely fringed with 

 cilia posteriorly. Antennæ powerfully developed, with usual 

 number of natatory setæ. Tail having terminal section rather 

 produced, its distal part gradually tapering and armed with 

 nearabout 9 pairs of lateral denticles, the most exterior biden- 

 tate; apical claws without any secondary teeth at base. Ephip- 

 pium with a single ampulla. 



Male having frontal part of head evenly rounded off. and 

 antennulæ armed at extremities with 3 strong incurved hooks. 



Body diaphanous, with a faint violet tinge along ventral 

 side of intestine. Length of adult female 1.14 mm; of male 

 0.63 mm. 



Remarks. — This form exhibits a perplexing similarity 

 to our common European species, M. brachiata. Jurine (= M. 

 rectirostris, Zaddach), so as readily to be confounded with it at 

 the first glance. However, on closer examination it presents 

 certain constant differences that undoubtedly should be regarded 

 as specific. Thus, the contours of the head. both in the female 

 and the male. would seem to differ a little from those in M. bra- 

 chiata. the front being less produced and the sinus above the 

 eye less distinctly marked. Moreover, the antennulæ in the 

 female are densely ciliate posteriorly. and in the male armed 

 with only 3 apical hooks. Finally, the terminal claws of the 

 tail want every trace of secondary teeth at the base. Another 

 Australian Moina. M. Macleana. has been described by Mr. King. 

 differing however materially. to judge from the description and 



