PECTEN. 163 
Stone of Cherry Hinton and Burwell. Zone of H. subglobosus of Hitchin. Lower 
Chalk of West Row near Mildenhall, and Stoke Ferry. 
Precten (CAMPTONECTES ?) GAULTINUS, sp. nov. Plate XXX, figs. la, b, 2. 
Description —Shell small, oval, a little higher than long, convexity small ; 
somewhat inequilateral, the antero-dorsal border slightly concave and longer than 
the postero-dorsal, which is shghtly convex. Kars very unequal. Apical angle 
from 95° to 100°. 
Right valve flattened, nearly smooth, with faintly marked, nearly straight 
radial ribs near the anterior and posterior borders, separated by narrow punctate 
grooves ; ribs and grooves absent or indistinct on the middle of the valve, except 
near the umbo. Anterior ear long, with a deep sinus, and three or four radial ribs 
crossed by growth-ridges. Posterior ear small, with its outer angle obtuse. 
Left valve rather more convex, with similar ornamentation. 
Measurements : 
(1) (2) (3) (4) 
Leneth ‘ 22 15 14 : 17 mm. 
Height : 19 ily : 16 : ik? ee 
(1—3) Gault, Black Ven. 
(4) Gault, Folkestone. 
Remarks.—This species differs from the typical Camptonectes m having the 
punctate grooves nearly straight instead of curving outwardly. 
Types—In the Woodwardian Museum, Cambridge. 
Distribution.—Gault of Folkestone and Black Ven. 
Sub-genus—Curamys, J. I’. Bolten, 1798. 
(¢‘ Museum Boltenianum,’ p. 165.) 
Prorun (Cutamys) risstcosra, Mtheridge, 1881. Plate XXX, figs. 3, 4, 5a, b, 
6 a—e, 7, 8. 
1881. Prcren risstcosta, Rh. Etheridge. In W. H. Penning and A. J. Jukes- 
Browne, Geol. of Cambridge (Mem. 
Geol. Survey), p. 141, pl. ii, fig. 1; 
pl. in, fig. 1. 
