712 
‘TEREBRATULA Gibbsiana, 
TAB. DXXXVII—fig. 4. 
Spec. Cuar. Suborbicular, rather triangular, ven- 
tricose, plaited plaits numerous, rounded, sim- 
ple; front much elevated with about 10 or 12 
plaits, flattened ; beak small, incurved, pointed ; 
small valve most convex. 
Tue length and breadth of this are equal without in- 
cluding the beak; it is therefore a much longer shell 
than T. lata, tab. 502, which it greatly resembles. 
Found in Greensand near Folkstone, in 1813, by Mr. 
Gibbs, an ingenious veteran collector well known to con- 
chologists a few years back. 
TEREBRATULA Mantelliana. 
TAB. DXXXVII.—fig. 5. 
Spec. Cuar. ‘Transversely obovate, gibbose, 
plaited ; plaits 16, sharp ; front elevated with 
A to 6 plaits ; beak prominent but small. 
Axourt one-fourth wider than long ; the plaits are large 
and simple; the front considerably elevated; the beak. 
is incurved and has a circular aperture. 
Abundant in the marl-pits at Hamsey, where it was 
collected by G. A. Mantell, Esq. in 1813. 
