EGERIA. DIMYARIA. 107 
The Tellinz inhabit the sea, burrowing in the sand, generally on flat shores. 
The recent species are numerous, and but few have been found in a fossil 
state: these are peculiar to the newer Tertiary formations, 
SUB-DIVISION III. —SOLENAIRES. 
Genus XXXVII.— PSAMMOBIA. — Lamarck. 
Generic Character. — Shell transverse, oblong, some- 
what angular, gaping at each extremity, and covered with a 
thin horny epidermis; with two short, bifid, cardinal teeth 
in the left valve, and one in the right valve; two distant, 
suborbicular, muscular impressions in both valves, situate 
near each end of the valve; pallial impressions with a very 
large sinus ; ligament external, and supported upon a pro- 
minent fulcrum. 
Psammobia solida. Plate IX. fig. 14. P. dubia. 
Plate X. fig. 1. 
The Psammobiz are marine shells ; and inhabit the tropical as well as the 
temperate seas. They are distinguished from the Telline by being destitute of 
the anterior marginal fold. Only a few species have been found in a fossil 
condition ; in the Blue Marls of France, and in the Oolitic group of rocks. 
The genus Psammotea of Lamarck is suppressed, and its species united 
with those of this genus. 
Genus XXX VIIL—SANGUINOLARIA. — Lamarck. 
Generic Character, — Shell equivalve, inequilateral, 
transverse, subelliptical, or ovate ; compressed, sometimes 
transversely oblong, and for the most part thin, and gene- 
rally covered with a glossy, olivaceous epidermis; length of 
the two sides of each valve varying in different species, and 
gaping at both extremities; margins generally rounded, but 
not parallel to each other; both valves provided with two 
cardinal teeth, but destitute of lateral teeth ; ligament ex- 
ternal, the fulcrum or space to which it is attached, gene- 
rally prominent ; two very irregularly shaped, lateral mus- 
cular impressions in each valve, the pallial impressions with 
a large sinus. 
Sanguinolaria Hollowaysii, Plate X, fig. 12. 
The shells of this genus inhabit the seas of tropical climates. They are but 
few in number. Fossil Sanguinolaria are rare, and occur in the Oolitic 
group. 
Genus XXX1X. — EGERIA. — Lea. 
Generic Character, — Shell generally subtriangular; two 
divergent cardinal teeth in each valve, one of which is cleft ; 
