456 Jones and Sherhorn — Tertiary Entomostraca. 



61. Cytheridba elongata, Brady. 



C. elongata, G. S. Brady. Monogr. Eecent Brit. Ostrac, Trans. Linn. Soc. 1868, 



vol. xxvi. p. 421, pi. xxviii. figs. 13-16 ; pi. xl. fig. 6 ; Monogr. Post-Tert. 

 Entom., 1874, p. 181, pi. ix. figs. 10-13. 



Numerous specimens from the Weybourn Crag of East Eunton, 

 varying slightly in individuality of growth and sex, are referable to 

 Brady's Cytheridea elongata. Collected by Mr, Clement Keid, F.G.S. 

 We have it also, not rare, in the Crag of Southwold (Norwich Crag). 



52. Kbithe glaoialis, B. C. and E,. PI. XL Fig. 15a, 15&. 

 B. C. and R. ' Monogr. Post-Tertiary Entom.,' Pal. Soc, 1874, p. 184, pi. vi. 

 figs. 21-24. 

 A smooth specimen of KritJie from the London Clay of Piccadilly 

 is so extremely close in every feature to K. glacialis from Scotland 

 and Norway, except in the apparent pitting of the latter, that we 

 cannot separate it from this later form. Sherborn and Chapman Coll. 



53. Keithe Londinensis, sp. nov. PL XL Fig. lla, lift. 

 Carapace narrow obovate, not quite semicircular in front, subacute 

 posteriorly. In edge-view the anterior third is compressed and 

 wedge-shaped, the middle is swollen, and the posterior third is com- 

 pressed, and ends in the usual notch formed by the produced ends of 

 the two valves. Surface smooth and shining. In this last feature it 

 resembles other forms of this genus, but in its outlines it differs 

 from any we know. From the London Clay of Piccadilly. Sherborn 

 and Chapman Collection. Bornemann's Bairdia pernoides (Zeitschr. 



D. g. Ges. vol. vii. 1855, p. 358, pi. 20, fig. 7) is a somewhat similar 

 KritJie of this geological age. 



54. Xestoleberis aubantia (Baird), 1835; var. 



Xestoleberis aurantia, Brady, Crosskey and Robertson, ' Monogr. Post-Tert. Entom.,' 

 Pal. Soc. 1874, p. 191, pi. xvi. figs. 32, 33. (Full synonymy is here given.) 



Except in being minutely punctate, and not distinctly papillose, 

 this specimen (from Headon) closely resembles the recent X. 

 aurantia, above quoted. From the Fluvio-marine deposits of Headon 

 Hill, Isle of Wight. Collected by the late F. E. Edwards, and now 

 in the British Museum. 



&5, Xestolebeeis Colwellensis, sp. nov. 



Carapace ovate in outline, and subovate in edge-view, with spinu- 

 lose surface. This is near X. aurantia (Baird), but blunter 

 anteriorly. 



From the Tertiary of Colwell Bay. T. E. Jones' Collection. 



56. Cythebuba Pbestwichiana, sp. nov. 



This belongs to the same type as Cytlierura nigrescens, B. C. and E., 

 * Post-Tert. Entom.,' p. 192, pi. xi. f. 28-32, but differs in its greater 

 compression anteriorly, and in being less strongly notched behind. 

 Allied forms are known to us from several Jurassic strata. From 

 the Belosepia-bed, Bracklesham. T. Eupert Jones's Collection. 



Named after Professor Prestwich, of Oxford, who has so greatly 

 advanced our knowledge of the Tertiary deposits. 



