46 THE ENTOMOSTRACA OF 



Var. insignis, nov. Plate VI, figs. 3 a — 3 c. 



INCH. 



Length,^ Lower Eocene: London. 



Right carapace-valve sub-triangular, depressed towards each end ; anterior border 

 with a slightly raised marginal rim : surface thickly punctate, pittings coarser towards 

 the middle, where they follow short sunken transverse lines. 



Dorsal aspect of carapace sub-fusiform. 



From the London Clay of the Copenhagen Fields, near London ; obtained with 

 others by Mr. J. Purdue during the cutting of the Great Northern Railway. 



Var. glabra, nov. Plate V, figs. 24 a, 24 b. 



INCH. 



Length, J T Lower Eocene ; London. 



Bight carapace-valve sub-triangular, depressed anteriorly ; similar in outline to the 

 right valve of C. perforata, but rather more angular before and behind; the two 

 extremities bordered by a slightly raised, smooth, marginal rim : surface smooth, not 

 punctate. 



Dorsal aspect of carapace acute-lanceolate. 



From the London Clay of the Copenhagen Fields, London. 



Sub-genus — Cytherideis, nov. Cgthere, Auctorum. 



Animal a Cgthere ? Carapace more or less triangular ; surface smooth, pitted, or 

 tuberculate : hinge-margin simple, except that, the central portion of the dorsal 

 margin of the left valve being somewhat incurved under that of the right valve (when 

 they are closed), the anterior and posterior angles of the dorsal margin of the left valve 

 remain somewhat projecting, and present internal shallow furrows for the reception of 

 the corresponding angles of the opposite valve : ventral margin partially incurved. 



This is a more distinct form of the hingement that generally obtains in Cupris. 



