Ostracoda new to Britain. 61 



that, though very much compressed, the tendency to a radiate 

 arrangement of the lacunse (?) is continuous throughout. 



I first found this species in a pond at Fenham, near Newcastle, 

 in April of the present year ; and it has since been taken by the 

 Rev. A. M. Norman in two ponds near Sedgefield, county Durham, 

 and again by myself near Whitburn, in the same county. 



Genus Candona, Baird. 

 Candona virescens, n. sp. PI. IV. figs. 1-5. 



Carapace elongated, compressed, rather higher in front than be- 

 hind ; ventral margin slightly sinuated ; dorsal margin very 

 gently arched ; anterior and posterior margins rounded. Sur- 

 face of the valves smooth. Seen from above, the carapace is 

 compressed, widest in the middle, and tapering gradually to- 

 ward the extremities. Colour a delicate sea-green, irregularly 

 variegated with markings of a lighter hue. Filaments of su- 

 perior antenna five long and seven short. Length -iH-o inch; 

 height -rer-o-o iiich. 



This species was found in considerable abundance in a shallow 

 weedy pond at Ashburn, near Sunderland, in May 1863. In 

 shape it closely resembles Dr. Baird's figures of C. similis; and 

 some specimens have, when fresh, two dark spots, which however 

 disappear on drying : they seem to correspond with the eye- and 

 muscle-spots. When I first found my specimens, I supposed that 

 they might prove to be merely the young of C. reptans, as they are 

 not unlike in shape to that species, though much paler in colour. 

 But the absence of any brush of setae on the lower antenna is of 

 itsel/ a sufficient character to separate the two species. I find 

 that even the very youngest specimens of C. reptans possess 

 these setae quite distinctly developed. 



Candona albicans, n. sp. PI. IV. figs. 6-10. 



Valves oblong. Dorsal margin straight, curving abruptly at the 

 posterior extremity, and more gradually in front; ventral 

 margin deeply sinuated ; extremities obtusely rounded off. 

 Surface of the valves uniformly and closely punctated, with a 

 few scattered slender hairs round the anterior and posterior 

 margins. Seen from below, the carapace is flattened, ovate, 

 and produced into a fillet at the anterior extremity. Colour 

 opake white, uniform or with pellucid patches. Length 

 .f-lfoinch; height -rfl^ inch. 



I took a single specimen of C. albicans (from which the ac- 

 companying drawings were made) in fresh water near Sunder- 

 land, in 1861. It has been found plentifully this year, in a 



