86 TERTIARY ENTOMOSTRACA OF ENGLAND. 



Three or four specimens of this form from Bracklesham, of which one is here 

 figured, differ individually from those previously figured in the 'Monogr.,' 1856, 

 and elsewhere, in their narrowness, the parallelism of their upper and lower 

 margins, and in the replacement of the curved dorsal ridge by a uniform marginal 

 rim. The very faint markings seen along the ventral ridge in the figures in the 

 'Monograph' of 1856, are more distinct in the specimens now under consider- 

 ation, and are evidently due to alternate thick and thin rod-like divisions, forming 

 minute light and dark squarish areas. The slight transverse dorsal notch in fig. 

 19 is also traceable in our present specimens, when carefully illuminated and 

 strongly magnified. 



Bi'acklesham. (British Museum.) 



11. Cythereis, sj). Thanet Sand. ' Monogr.,' 1857, p. 40, pi. vi, fig. 17. 



XIII. CYTHERIDEA, Bosquet, 1852. 



Valves generally subtriangular and usually punctate. Hinge-margins tuber- 

 culate or crenulate, chiefly towards the ends, but sometimes all along. See 

 Jones (' Monogr. Tert. Entom.,' 1857, p. 41), Brady (' Trans. Zool. Soc.,' vol. v, 

 1866, p. 369), and Jones and Sherborn (' Proceed. Bath Nat. Hist, and Antiq. 

 Field Club,' vol. vi, 1888, p. 251). 



1 & 1*. Cytheridea torosa (Jones), et var. teres, Brady Sf Eobertson. 



Ctpeideis toeosa, Jones. Monogr. Tert. Entom., 18.57, p. 21, pi. ii, figs. I a — i 



(fig. 1 e being the smooth form " teres " =.Cytlieridea 

 littoralis, Brady). 

 Cttheeidea toeosa, Bradi/, Crosshey & Robertson. Monogr. Post-Tert. Entom., 

 1871, p. 178, pi. XV, figs. 11 and 12 ; and var. teres, 

 Brady and Eobertson, ibid., p. 179, pi. 7, figs. 1 and 2. 



There has been much confusion in the nomenclature of tliis species, and its 

 history may be seen in the synonymy given in the above references. G. torosa is 

 fossil at Mundesley in Norfolk, and at Grays, Essex; var. teres at Wear Farm and 

 Chislet ; and in the peat-bed at Tilbury. Several Post-Tertiary localities are 

 quoted by Brady, Crosskey and Robertson, p. 179, for (7. torosa and the var. teres. 

 (Brit. Mus., &c.) 



' Zeitschr. deutsch. geol. Gas.,' vol. vii, p. 282), which is possibly G. coronata, Roemer (?) ; fig. 18 b 

 is a poor specimen probably of C. ceratoptera, Bosquet (see Bosquet, 'Entom. Tertiair.,' p. 117). It 

 may be C. alata, Bosquet (Jones, ' Monogr. Cret. Entom.,' p. 21, pi. v, fig. 14). 



