156 CRETACEOUS LAMELLIBRANCHIA. 
1900. Puricatuta CarTERONIANA, Wollemann. Die Biv..u. Gastr. d. deutsch. u. 
holliind. Neoc. (Abhandl. d. k. 
preuss. geol. Land., n. F., pt. 
31), p. 22. 
Description.—Shell oval, somewhat triangular, oblique; height greater than 
length. Right valve much inflated, ornamented with usually eight to ten sharp, 
prominent ribs, which are slightly curved, bear short spiny processes, and are 
separated by broad furrows; well-marked growth-lines occur at intervals. Left 
valve flat or slightly concave; ribs less prominent, more rounded, and broader 
than on the right valve, separated by narrow furrows. 
Measurements : 
(1) (2) (3) 
Length ie 15 11 mm. 
Height’. ; 2 ; 2] 16 Wah. 
(1—3) from Upware. 
Types.—From the Neocomian of Maisons, near the Ecorces (Doubs). The 
specimen figured by Keeping is in the Woodwardian Museum. 
Distribution—Hythe Beds of Hythe and (Bargate Stone) of St. Catherine’s 
Hill (Guildford). Sandgate Beds of Sevenoaks. Lower Greensand of Brickhill, 
Potton, and Upware. 
PLicaTuLA mQuicostata, Keeping, 1883. 
1883. PuicaruLta mquicostata, W. Keeping. Foss., etc., Upware and Brickhill, 
yee LILIES alle iz ails GE 
Deseription.—Shell small, ovate, oblique, high, very inequivalve, margins 
rounded. Right valve much inflated, umbonal part prominent, with a small area 
for attachment ; ornamented with numerous (about fifty) small, regular, rounded 
ribs, which curve slightly, are of nearly equal size, and are separated by narrow 
grooves; these ribs are crossed by small concentric lamelle, and occasionally by 
‘stronger growth-lines. Left valve flat or slightly concave, with similar ornamenta- 
tion, but the ribs apparently fewer and broader. 
Measurements : 
(1) (2) 
Length . : : ; : : iy) 16. mm. 
Height . : : 3 : : 14. NgPsy 
Thickness ‘ ; : : : 8'°5 ili + 
(1, 2) from Upware. (1) the type. 
' Measured obliquely. 
