16:2 BRITISH ENTOMOSTRACA. 



than posterior, upper margin slightly arched, ;nid inferior 

 edge somewhat sinuated. The valves are flatter than in 

 almost any other speeies, pellucid, and quite smooth. 

 The colour is of a dull white, without any spots or marks. 

 The (.'. (fi'/ccfa of Miiller is quite a different species from 

 the j\fonoc. conchaceus of Jurinc, though that author 

 quotes them as synonymous, in which, though with hesita- 

 tion, he is followed by M. Edwards. These synonyms, 

 therefore, as quoted by me in the ' Mag. Zool. and Bot.,' 

 must be expunged. 



Hal). Neighbourhood of London ; Pool on Beaumont 

 Water, &c. ; not common. 



5. CANDONA SIMILIS. Tab. XIX, figs. 2, 



CANDONA SIMILIS, Baird, Trans. Bcrw. Nat. Club, ii, 153, 18-i5; Ami. 

 and Mag. Nat, Hist., xvii, 415, t, '.), f. I. 



Shell somewhat elliptical in figure, flat, slightly sinu- 

 ated in the middle of the lower margin, and nearly plain 

 on dorsal edge. The colour is white, with two dark- 

 orange spots on the back. The valves arc smooth, except 

 round the edges, which are fringed with rather stiff hairs ; 

 these are more numerous on anterior extremity than on 

 posterior. The shell is narrower posteriorly than ante- 

 riorly, and is transparent. Its motion is very deliberate, 

 when it walks along the plants, first putting one foot for- 

 ward, and then leisurely drawing up the other. It ap- 

 proaches near to the ( '. i/c/ccfa of Midler ; the posterior 

 extremity, however, is narrower than anterior, which is 

 the reverse in the 



Huh. Pond on Clapham Common, July 1S4G. 



11 

 ( vi m.iUNEN, Kwmcf, Jahrbucli, 1838. 



/.- -Two pairs of antenna";; superior not fur- 

 nished with the pencil of long filaments. Feet, three pairs. 



This family eoniains 1 wo British genera ( 

 and CYTIII 1:1 [8 



