17 
PECTUNCULUS PULVINATUS, Tab. 2, fig. 2. 
Orbicular, convex, subequilateral, with numerous radiating 
striae; beaks small, central; hinge edentulous in the centre; in- 
ner margin with approximate angular lines or teeth. 
Localities. York Town, Suffolk, Ya. Upper Tertiary. 
Syn . Pectunculus pulvinatus, Lain . Jin. sans Vert. vol. 6. 
p. 54. 
This shell is very common in France and Italy. Lamarck 
describes three varieties, and observes that he believes it to be 
analogous to P. glycimeris. 
In the vicinity of York Town, it is washed out of the high 
sandy banks, accompanied by the following species, from which 
it can always be distinguished by its orbicular form, &c. 
PECTUNCULUS SUROVATUS, Tab. 2, fig . 3. 
Suborbicular or subovate; inequilateral; with radiating sulci, 
becoming obsolete with age; hinge, with the series of teeth cut 
off, and nearly obliterated in the centre, by a rectilinear line; 
teeth largest on the shorter side of the valve ; marginal teeth 
broad and separated. 
Syn. Pectunculus subovatus, Say. Journ. A. N. S. v. 4,p. 
Pectunculus variabilis? Sow . Min. Con. v. 5, t. 471. 
Localities. York Town, abundant; Suffolk, Ya. Upper Ter. 
If this should prove to be identical with P. variabilis , it will 
be an interesting species in consequence of its being character- 
istic of the same formation in Europe and America. 
MUREX UMBRIFER. Tab. 3. fig. 1. 
Fusiform, with 6 foliated reflected laminae; whorls angular 
and carinated; aperture obovate; beak recurved. 
Localities . James River; York Town, Ya. Upper Tertiary. 
FUSUS EXXLIS. Tab. 3, fig. 2. 
Fusiform, elongated, with longitudinal undulated ribs, and 
revolving striae, acute, elevated and alternately smaller; beak 
produced, nearly straight; aperture half the length of the shell. 
Locality , James River. Ya. Upper Tertiary, 
