390 Jones and Sherhorn — Tertiary Entommtraca.. 



19. Cythere Charlesworthiana, sp. nov. 



A neat small Cythere, oblong, with front end rather obliquely 

 rounded, and the posterior nearly square. Ventral edge slightly 

 incurved, dorsal faintly arohed. Broadest at the anterior third near 

 the front hinge-joint. Surface ornamented with very delicate elon- 

 gate pits, arranged in lines lengthwise, but curving in front, parallel 

 with the margin. The anterior margin is neatly denticulate, espe- 

 cially on its dorsal third. This differs from our Cythere recurata 

 in being truncated posteriorly and denticulated in front, and also in 

 its ornament. The form nearest to this that we know of is C. tenera,. 

 G. S. Brady, Trans. Linn. Soc, vol. xxvi. p. 399, pi. 28, fig. 29-32 ; 

 but in shape and ornament it differs. 



From the Weybourn Crag of East Eunton, collected by Mr. 

 Clement Eeid. (Mus. Pract. Geol.) 



In memory of his early researches in the Crag, we name this 

 species after Mr. E. Charlesworth. 



20. Cythere villosa, Sars. B. C. and E., Monogr. Post-Tert. Entom. 

 1874, p. 157, pi. iii. figs. 7-13. 



Subtriangular, straight on the ventral, and obliquely arched on the 

 dorsal and front edges, but somewhat truncate behind. Surface 

 bearing a concentric reticulation of coarse angular pittings. Three 

 tubercular swellings affect the valve just within its thickened rim, 

 two behind, such as are frequent in this group of Cyiherce, and one 

 in the antero-ventral third. The greatest convexity of the valves is 

 central, making the edge-view acute-oval. 



From the Weybourn Crag of East Eunton. Collected by Mr. 

 Clement Eeid. (Mus. Pract. Geol.) 



With this species we connect a variety from the "Norwich Crag" 

 of Southwold, in which the tubercles are not so definitely marked. 

 The places of the two near the ventral margin are occupied by 

 irregular swellings, and the postero-dorsal tubercle is ill-defined, 



21. Cythere l^sa, sp. nov. 



Ovate-oblong, straighter on the ventral than on the dorsal edge- 

 Close to the ventral margin is a broad, longitudinal, somewhat sinuous 

 ridge, widened, or rather doubled, with an oval interspace at its 

 posterior third, and irregular at the anterior third. In one specimen 

 the surface is coarsely reticulate with angular meshes ; in the other, 

 the ornament consists of a smaller mesh-work. In this latter indi- 

 vidual the edge-view is less convex than in the other. 



Norwich Crag, Bramerton. Collected by Mr. Clement Eeid. (Mus. 

 Pract. Geol.) 



22. Cythere Woodwardiana, sp. nov. 



Sub-trigonal ; obliquel3'- rounded in front, nearly semicircular 

 behind ; broad across the anterior third by the projection of the 

 hinge-joint. Surface slightly convex ; ventral surface somewhat 

 flattened. Superficial ornament a coarse irregular pitting. 



We name this species after Dr. Samuel Woodward, one of the 

 earliest workers in these late Tertiary deposits. 



