PHOLAS. PIDDOCK. 
143 
PHOLAS. PIDDOCK. 
\ 
Shell with two large primary valves* open at both 
ends, and several lesser ones about the hinge: 
teeth long, incurved* one in each valve on the in¬ 
side. 
* 1. Pholas Dactyl us. Prickly Piddock. 
Lhter, pi. 433. f. 276, and App. pi. 19. f. 1 , 2 — Pennant, 
I- 42. f. 1— Da Costa , pi. 16. f. 2— Donovan, pi. 118— 
M, pi. 13. f. 1,2,3— Dorset Cat. pi. 3. f. 2. 
Shell very thin, white or with a ferruginous tinge, ob- 
hag-Oval, sometimes distorted, ribbed longitudinally* and 
irate transversely in a fainter manner ; the ribs on the 
lirgerend beset with numerous small concave spines, which 
awards the smaller end become thin scales : at the larger 
end is a vast oval gape in front, where the margins slope 
hto a curve on each side, the edges of which are generally 
fringed with spines and reflected on the back ; the smaller 
(oil elongated and gradually sloping into an obtuse rounded 
1 point, where is also a large gape: hinge reflected on the 
feck, separated by transverse scaly partitions into from 
twelve to sixteen cells, which are covered with two oblong 
very thin plates or rather membranes connected length- 
wap, and supported by another triangular strong plate at 
tic bottom j below the hinge is also another long narrow 
thin plate attached to the sides of each valve by a connect- 
ig membrane, and reaching nearly to the smaller end : 
feth long, curved, flat and broad towards the top, where 
they are rounded and ribbed : length sometimes two inches, 
std six in breadth. 
Bunowed in sandstone, wood, and clay. v. v. 
2. Pholas parva. Small Piddock . 
Montagu, pi. l.f. 7, S— Pennant, pi. 43. f. 1. 
Shell oval, rough, white, striate transversely and longi¬ 
tudinally, except at the smaller end which is sometimes 
covered with a rough brown wrinkled skin ; the larger end 
doping into a beak like the last* and forming a very wide 
