CYTHEREIS. 
175 
1. Cythereis Whiteii. Tab. XX, figs. 3, 3 a* 
Shell oblong, flat, thin, somewhat narrower at one end 
than at the other. Larger extremity rounded ; the nar- 
rower extremity somewhat truncated and strongly toothed. 
The anterior margin and rounded extremity are crenulated 
throughout the whole of their length, and have placed 
above them a sort of shelf or pinched-up fold, which runs 
parallel with the margin, and which is strongly serrated. A 
sharp crest, which is crenulated, runs along the centre of the 
valve. The posterior margin is nearly straight and smooth. 
This species is remarkably handsome, and approaches 
near the Cypridina serrulata of Bosquet (Entomost. de 
la Craie de Maestricht, t. iv, f. 2, a , b) 9 but is distin- 
guished from it by being shorter and broader, and by the 
margin being continued straight to the end, and not in- 
terrupted and toothed, as in that species. 
Hab. — Torquay, in sand; W. C. Williamson, Esq. 
Tenby, in sand ; T. Rupert Jones, Esq. 
2. Cythereis Jonesii. Tab. XX, fig. l.f 
Shell thick, oblong oval, rather broader at one extre- 
mity ; the narrower end flattened, with seven strong teeth 
projecting from the edge, the outer teeth on each side 
being the strongest ; the broader extremity rounded and 
convex. The centre of the shell is plane and smooth, and 
round the whole circumference there is a raised border or 
narrow plate, which is perforated at frequent intervals by 
open loop-holes. 
This . species approaches the Cytherina coronata of 
Roerner (vide Jahrbuch, 1833, t. vi, f. 30) in structure, 
but differs totally in form, and in having the strong teeth 
at narrow extremity. 
Hab . — Isle of Skye, in sand ; W. C. Williamson, Esq. 
* Named after Adam White, Esq., of the British Museum, well known 
as the able describer of many new species of Crustacea. 
f Named after T. Rupert Jones, Esq., author of the c Entomostraca of 
the Cretaceous Formation,’ whose attention in forwarding me specimens of 
Ostracoda for examination I thus gladly acknowledge. 
