18 G-. O. Sars. 



7. Moina australiensis, G. O. Sars, n. sp. 

 (PI. 3.) 



Specific Characters. — Shell of the usual appearance, 

 varying in female considerably in form, according to the 

 degree of distention of the matrix. Head in female not 

 very large, and somewhat procumbent, being evenly vaulted 

 above, with a very slight, though distinct sinus above the 

 eye, front not much produced and obtusely rounded, ventral 

 edge but very slightly convex at the insertion of the anten- 

 nulæ. Head in male comparatively much larger, sub-erect, 

 and less strongly vaulted above, frontal part obtusely trun- 

 cated, ventral edge straight. Eye of moderate size. Auten- 

 nulæ in female comparatively short, subfusiform, in male 

 about the length of the head, and armed at the tip with 4 

 strong claws. First pair of legs in female with the sub-api- 

 cal seta simple, ciliated; those in male having, in addition 

 to the usual claw, an unguiform spine and a long terminal 

 seta. Caudal claws quite smooth. Ephippium with 2 egg- 

 ampullæ placed obliquely transversally. Body pellucid, in 

 female with a more or less distinct orange hue. Length of 

 adult female 1,30 mm., of male 0,80 mm. 



Hem arks. — This form exhibits several points of agree- 

 ment with the European species M . paradoxa, Weismann, and 

 indeed at first I belived it to be the very same species. Being 

 however acquainted with another Australian species, which ex- 

 hibits a similar agreement, and having instituted a closer com- 

 parison between the European species and these 2 Australian 

 forms, I am now induced to regard them as being speci- 

 fically distinct. From M. propinqva, the present species is 

 easily distinguished by the rather different form of the head, 

 the structure of the 1st pair of legs in the male, and by the 

 ephippium having 2, instead of a single egg-ampulla. 



