CYTHERELLA CHAPMANI. 49 



Localities. — Ganlt, Godstone, Surrey, and Folkestone, Kent. Collected by 

 Mr. F. Chapman. 



5**. Cythbbella Williamsoniana, Jones, var. (jranuJosa, Jones. Plate III, figs. 



68, 69, 72. 



Cttheeella Williamsoniana, var. granulosa, Jones. Monogr. Bntom. Cret., 



1849, p. 31, pi. vii, fig. 26 i. 



— — (?), Bosquet. Mem. Comm. geol. Neerlande, 



vol. ii, 1854, p. 62, pi. v, figs. 

 2 a— d. 



— — var. BosQTTETi, Marsson. Mittheil., &c., 1850, 



p. 31, pi. ii. figs. 8 d, e. 



Length '72 ; height '42 mm. 



Larger than the type specimens, roughened with granules and small tubercles. 

 The marginal elevations on the valves are subject to the same modifications of 

 direction and extent as in the ordinary forms, and may be narrowed as ridges, 

 with or without granulations. 



The specimen figured by Bosquet, op. cit., 1854, appears to be var. granulosa. 

 In his opinion, however, the granulations are present on adults, but are lost more 

 or less on old individuals. 



Dr. Marsson's figs. 8 d and 8 e almost supply the counterpart of fig. 26 i (not 

 reproduced here). 



Localities. — Chall-, Norwich, Horstead, Magheramorne (Antrim) ; Chalh-roch, 

 Dunstable ; Gault, Folkestone. 



Foreign. — Chall-, Maastricht and Riigen. See also Reuss, ' Elbthalgeb.,' pp. 

 153 and 154. 



6. Cytiierella Chapmani, sp. nov. Plate III, fig. 70. 



Length '52 ; height "3 mm. 



Small, short, stout, and flat, sub-oblong, slightly ovate ; bearing just within 

 the front, back, and rear margins a nearly continuous ridge, and within it a set of 

 unequal longitudinal ridges or riblets, of which one is free, and the others 

 apparently form a compressed spiral. 



Some small Gytherellx closely approaching G. Ghapmani are in Mr. F. 

 Chapman's Collection from the Gault of Folkestone. 



Locality. — Gault, Godstone, Surrey. Collected by Mr. F. Chapman. 



7 



