PS A M M O B I A . Aiictorum . 
Gen. Char. A transverse, elliptical, or ovato- 
oblong, bivalve ; depressed, slightly gaping 
at the sides ; beaks not incurved ; hinge 
furnished with two teeth in the right valve, 
and one in the other. 
A genus nearly related to Tellina, blit distinguished by 
the absence of lateral teeth in the hinge ; some species 
have a general curvature of the valves to one side, but 
not the irregular twist in the margin peculiar to Tellina ; 
many of the species are prettily marked, and most of 
them are furnished with an epidermis. There are three 
internal impressions from the attachment of muscles, one 
of them irregular and small is placed near the beak ; there 
is also a deep sinus in the line to which the mantle was 
attached ; one tooth in each valve is commonly bilid. 
The recent species are inhabitants of the sea in various 
latitudes. 
PSAMMOBIA solida. 
TAB. CCCXL1I. 
Spec. Char. Transversely elongated, depressed, 
tumid, nearly smooth, slightly curved ; an 
obtuse carina marks the anterior side. 
1ST early twice as wide as long : a thick bluntly shaped 
shell, with a slight oblique truncation upon the anterior 
extremity ; it is more gibbose or tumid, although upon 
the whole not deeper than P. Ferroensis, which it some- 
