BRITISH FRESH-WATER ENTOMOSTRACA. 535 



The variety which I have referred to as " brevicornis," under 

 the mistaken impression that it was C. hrevicornis Clans, may, 

 however, really be a good species. It is always distinguished by 

 its smaller size, its pelagic habit, and the absence of setae on the 

 inner edges of the caudal rami. It has only been seen in the 

 south- east of England. 



C. diaphanus Fischer [Schmeil (44)]. 

 C. longicaudatus Brady (36). 

 Apparently a very rare species. Brady (36) only mentions it 

 from one locality, Ebbesborne, near Salisbury, and I have taken 

 it on Household Heath, Norwich. No further records are known. 



C. bicolor Sars [Schmeil (44)]. 



C. rubellus Lilljeborg [Lilljeborg (40)]. 



Miss B. Sprague (55) has lately put this on record as a British 

 species, I have found it also in the same locality (Lake District), 

 and Mr. Robert Gurney informs me that he has found it in the 

 " Broads " district. 



C. varicans Sars [Schmeil (44)]. 



C. fuscus (Jurine) [Schmeil (44)]. 



C. quadricornis var. c. Baird (1). C. coro?iaiz6s Lubbock (42). 

 C. signatus Brady (35) and in part (36), Scourfield (26). 



C. bistriatus Koch [Schmeil (44) = C. cdbidus var. distinctus ; 



Lilljeborg (40) — C. distinctus]. 



As I have already stated (29), I believe that this form must 

 be referred to Koch's C. bistriatus (39). The vexed question as to 

 whether it is a good species or a hybrid between C. fuscus and 

 C. cdbidus has not yet been settled so far as I am aware. It has 

 only hitherto been found in the south and east of England. 



C. albidus (Jurine) [Schmeil (44)]. 



C. tenuicornis Lubbock (42), Brady (35), Scourfield (26). 

 C. signatus Brady (36) in part. 



C. serrulatus Fischer [Schmeil (44), Brady (35, 36) ]. 



This extremely common species has long been recognised as 

 exhibiting considerable variation, and Lilljeborg (40) has pro- 

 posed to divide it into three distinct species — viz. C. serrulatus in 

 the strict sense, C. macruroides, and C. varius, the latter being 

 further subdivided into the three new varieties, speratus, proximus, 



