222 
POLLICIPES. maximus. 
TAB. DCVI.—/igs. 3—6. 
Spec. Cuar. Terminal valves rhomboidal plane, 
except sometimes a central ridge, and lines of 
growth ; posterior valve arched, lanceolate, 
much elongated. 
Tus differs from the last in the narrowness of the pos- 
terior valve (fig. 4.), and smoothness of the terminal valve 
which in old valves (fig. 3.) has a furrow along its middle 
in place of a ridge (fig. 5.); the anterior valve (fig. 6.) is 
hooked and has an obtuse keel. We are not acquainted 
with any other valves; and in this limited state of our 
knowledge, we must confess that it is with some degree 
of hesitation we declare these two species as distinct from 
each other. 
From the Upper Chalk, collected by Mr. Barnes at 
Norwich. The posterior valve (fig. 4.) is from North- 
fleet. 
POLLICIPES reflexus. 
TAB. DCVI.—fig. 8. 
Spec. Cuar. Lateral valves nearly flat, smooth ; 
posterior valve lanceolate, straight or recurved. 
A smaux smooth species, found by G. E. Smith, Esq. in 
Colville Bay in the Isle of Wight, among sand accom- 
panied by many minute shells and valves of Chitones, 
and probably connected with the so called upper marine 
formation, 
