68 CRETACEOUS GROUP 
bles Sowerby’s SANGUINOLARIA undulata, tab. cxlvii, 
fig. 2. 
' PHOLADOMYA. 
P. occidentalis, (5S. G. M.) PI. viii, fig. 3. 
Specific character. Oblong-ovate, anterior margin rounded, 
ventricose; posterior margin obtusely truncated, compressed ; 
with twenty-five or thirty narrow, elevated, sub-tortuous coste, 
having much broader, slightly concave, intervening spaces. 
Length, three inches; breadth, about one-third less. 
I have examined five imperfect specimens in the Aca- 
demy, all of which differ in the number and relative po- 
sition of the coste. Mr. Featherstonhaugh possesses a 
perfect cast. 
From the excavations of the Chesapeake and Delaware 
canal. 
PHOLAS. 
P. ctthara, (S.G. M.) PI. ix. fig. 10. 
Specific character. Ovato-cuneate, ventricose, cancellated, 
with an oblique groove passing from beak to base. 
Length, three-fourths of an inch. 
Obtained from the blue marl of Monmouth county, N. 
Jersey, by Lieut. Mather, to whose kindness I am in- 
debted for an opportunity of describing and figuring it. 
TEREDO. 
T. tebialis, (S.G. M.) PI. ix, fig. 2. 
In the former edition I referred this species to T, an- 
