Sr MARGUERITE HENRY. 33 



was obtained from the Lane Cove River near Gordon, from Kendall and Corowa, 

 It also occurs in Queensland, Ceylon, New Guinea and Java. 



There has beien a controversy as to whether the forms C'eriodaphnia rigaudi 

 Richard and C. cornuta Sars are specifically distinct. Daday (1898) united them 

 on the grounds that he had found an intermediate series of forms. Stingelin 

 (1904) maintained that they were distinct species. Daday in 1910 reasserted 

 his view and ag'ain mentioned finding intermediate forms. Delaehaux (1917, p. 

 81) examined specimens collected in the neighbourhood of Lake Victoria Nyanza, 

 and noted that all those which had two sj^ines on the head had also a double 

 posterior spine. He also pointed out differences in the structure of the ventral 

 edges of the carapace and in its sculpture. — "Tandis que chez les premiers (C. 

 cornuta) ces bords sont munis d'eeaiUes ou de dents decoupees en scies, chez les 

 seconds (C. rigaudi) ces eeailles presentent un bord a peu pres droit. Chez la 

 forme cornue du reste, toute la structure des teguments parait plus fortement 

 developpee, le reseau hexagonal de la carapace est mieux marque et fortement 

 en relief." Sars (1901) mentioned this diffei'ence in sculpture and also the fact 

 that a form of C. rigaudi did exist with two spines on the head. This species 

 was never very plentiful in the collections. About a dozen specimens were found 

 that were normal for C. cornuta, but there were some in which the spine taking the 

 place of the rostrum was present alone, but in which there were two 

 distinct points at the posterior end of the carapace; about ten specimens were 

 typical of C. rigaudi; there were none which bore two head spines and a single 

 posterior spine. In regard to the markings of the carapace edges as observed 

 by Delaehaux, the majority of the typical C. cornuta forms had the saw-like 

 markings, but some had not, and these forms had a weaker reticulate sculpturing. 

 It is noteworthy that the two forms were always taken together. It would ap- 

 pear from these examples that the species ai'e not distinct but that C. cornuta 

 is very variable. Delaehaux points out that the characters by which he distin- 

 guishes them are subject to variation. In two of the specimens examined a short 

 spine was present immediately in front of the cervical sinus. 



Ceriodaphxia spinata Henry. (Plate iv., fig. 5.). 



Proc. Roy. Soc. N.S.W., lii., 1918 (1919), p. 466. 



Distribution. — N.S.W. : Holbrook, Corowa. 



Cebiodaphnia honorata (King). 



King (1852, p. 249) described and figured this form under the name of 

 Daphnia honorata. It is undoubtedly not a member of the genus Daphnia but 

 belongs to Ceriodaphnia. As I have not been able to obtain a specimen I quote 

 King's original description. 



"Carapace oblong, dorsal margin often concave, the surface reticulated in 

 an irregnlar pentagonal manner. The spine at the extremity is very short. An- 

 tennules large. Antennae also large, basilar joint having a crenation carrying 

 two setae. The first joint of the posterior branch is as long as the remaining 

 two and as long also as the fii^st three of the anterior branch. Setae not 

 plumose." 



Locality. — Varroville near Campbelltown. 



Both King and Sars pointed out that this species is most nearly related to 

 Ceriodaphnia r<sticulata (Jurine) though distinct. It is also distinct from the 

 two preceding species. 



