Fresh-water Entomostraca of South America. 1 7 



dorsal margin somewat arched, front narrowly rounded, 

 ventral margin almost straight and horizontal, forming 

 at the place where the antennulæ are attached a slight 

 protuberance, as a rudiment of the rostrum; fornix very 

 prominent and extending to the front. Eye of moderate 

 size, with very distinct crystalline cones; ocellus easily 

 observable at a short distance behind the eye. Antennulæ 

 equalling in length about the distance from the front to 

 the base of the labrum, sensory bristle about in the middle, 

 apical papillæ very small. Upper ramus of antennæ con- 

 siderably longer than the lower, apical spine almost of the 

 same length as the terminal natatory setæ. Tail very 

 slender, its distal part being narrowly conical in form, infra- 

 anal denticles about 10 on each side, caudal claws of 

 moderate size and smooth, caudal setæ scarcely exceeding half 

 the length of the caudal part, and uniarticulate. Body 

 highly pellucid and generally hyaline, only in large specimens 

 sometimes tinged with a faint rose or carneous tinge. Length 

 of fully grown female about 1 mm. 



Remarks. — The description and figure given by 

 King of his Moina Macleayii are certainly rather imperfect, 

 but fully suffice to prove that it is a true member of the 

 genus Moinodaphnia, as defined by Mr. Herrick, and I 

 cannot see anything which could forbid its identification with 

 the Brazilian form here treated of. I am also quite assured 

 that the Moina submueronata of Brady, of which I have 

 had specimens for examination, is the very same species. 

 This in my opinion, is also, the case with Moinodaphnia 

 Macquerysi of Richard. The North American form, M. 

 alabamensis Herrick, on the other hand, may perhaps be 

 specifically distinct, as it is of considerably larger size, and 

 also, to judge from the figures given, differs conspicuously in 



2 — Archiv for Math, og Naturv. B. XXIII. Nr. 3. 

 Trykt den 11. Marts 1901. 



