34 TERTIARY ENTOMOSTRACA OE ENGLAND. 



at the posterior slope, like the other. The ventral aspect of the carapace is 

 cuneiform or almost sagittate. G. H aiding eri, Bosquet (' Entom. Tertiair.,' p. 125, 

 pi. vi, fig. 10), is near to this species in general characters; but its more angular 

 shape, and more symmetrical network, distinguish it. So also G. Edwardsii 

 (Roemer), Reuss (' Haidinger's Nat. Abth.,' vol. iii, p. 84, pi. x, fig. 24), is like it 

 to some extent ; but its ridges extend the whole length of the valve, joining fore 

 and aft, and, as figured by Bosquet (' Entom. Tert.,' p. 94, pi. iv, fig. 14), it appears 

 still coarser or stronger, and with still more marked features. 



Several specimens from the London Clay, Piccadilly, London. Collected by 

 Messrs. Sherborn and Chapman. (British Museum.) 



6. Cythereis Bowerbankiana, Jones. 



Cytheeeis Boweebankiana, Jones. Monogr. Tert. Eutoni., 1857, p. 39, pi. vi } 



figs. 7, 8; Geol. Mag., 18S7, p. 452, 

 pi. xi, fig. 9. 



This is characteristic of the London Clay. One specimen has been found by 

 Mr. C. D. Sherborn at Whitecliff Bay, and a few others have been long known from 

 Copenhagen Fields and Wimbledon Common, near London. (British Museum.) 



7. Cythereis horresoens, Jones, 1857, comes next in the order of form and orna- 



ment. It belongs to Barton and Bracklesham. The late Mr. F. E. Edwards 

 found it also at Highcliff. (British Museum.) 



8. Cytuereis si'Iniferrima, sp. nov. Woodcut, Fig. 3. 



Cytiiebeis spinossissima, 1 Jones & Sherborn. Geol. Mag., 1887, p. 453, woodcut, 



fig. 2. 



A right and left valve of this form were lately found, with G. Harrisiana, in 



some washings of the London Clay from Piccadilly. They are oblong, with the 



front margin broader and more semicircular than the hinder. Surface coarsely 



reticulate; the reticulations becoming more shallow and indistinct as they reach 



the central area. Many of the ridges of the meshes are pinched up at their 



junctions, and in most cases thus form bluntly-pointed spines ; these spinous 



prolongations are partly the cause of the confusion of the reticulation in the 



central area. Approaching the margins, the spines become longer and more 



defined ; and the anterior area bears, in addition to its marginal row of spines, a 



second row just within the other. In this form, related to G. Botverbankiana on 



the one hand and to G. horrescens on the other, we note that the characteristic 



1 This name is preoccupied in the ' Trans. Zool. Soc.,' 1865, p. 386 



