286 GINGLYMACONCHA. VENERIDZ. 
This species, which is by far the most common, is found on 
most of our coasts, preferring such as are sandy or composed 
of shingles. 
They are eaten by the inhabitants of the*southern coast of 
Devon, and are sometimes named Hens. 
Genus 33. DorRvILLEA. 
Shells triangularly orbicular ; the hinge under the umbones, 
and before and behind the cardinal ligament, with two equal 
lamellee forming an angle. 
The animal with its tracheal tubes very unequal, not ciliated ; 
the upper one very short ; the under one very long. 
DorvVILLEA ANGLICA. 
Shells very thin; the epidermis very smooth, pale testa- 
ceous. Length three-eighths; height two-eighths and one 
half of the eighth of an inch. 
I discovered this new species in some salt pools near the sea- 
shore near Bexhill in Sussex, in great abundance on a marine 
Ulva; but could not find it in the neighbouring sea. 
FAMILY X. VENERIDZ. 
The shells shut; the valves equal; the cardinal ligament 
exterior and hinge-shaped; the hinge is angulated and fur- 
nished with teeth. 
Stirpium Synopsis Artificialis. 
A. Lamella ante et pone dentes cardinales locata. 
a. Dentes cardinales divergentes. 
Stirps i. Testze valvis eequaliter convexis. 
Sterps 10. Testee valvis compressis. 
