Fresh- water Entomostraca of South America. 1 9 



green nutritive yolk, being apparently, as is stated by Prof. 

 Weissman in the case of Moina, nourished during their 

 development by some fluid secreted from the body of the 

 mother. Indeed, a very distinct cellular layer is always 

 found in gravid females extending along the part of the 

 back bounding the matrix below, and no doubt this layer 

 is of glandular nature, forming the so-called «Nährboden» 

 of Weissmann. To prevent the fluid from escaping from the 

 matrix, the closure of this cavity behind is more complete 

 than in most other Cladocera, being effected by a peculiarly 

 formed dorsal projection, from which a distinct fold extendes 

 forwards on each side of the body (see figs. 1, 5). 



Occurrence. — The aquaria in which this form 

 appeared, were prepared with mud, partly taken at Itatiba, 

 partly at Ipiranga. 



Distribution. — If my identifications are cor- 

 rect, this form has a very wide geographical distribution, 

 occurring, not only in Brazil, but also in Australia (King), 

 Ceylon (Brady), Congo (Richard), and New Guinea (Daday). 

 I am moreover enabled to state the occurrence of this form 

 also in Sumatra, some well-marked specimens having been 

 found in a plankton sample from the Helvetic Estate. 



Gen. Ceriodaphnia, Schödeler. 

 Remarks. — Several species, of this well-known 

 genus, some of them identified with European ones, have 

 been recorded from South America; but none of them have 

 been described or figured in such a manner as to be dis- 

 tinctly recognizable, some having been simply enumerated as 



