Pvn H,i I'UitlS

ASTARTE. 315
This species is the Venus Danmonia (properly Dam-
nonia) of Montagu, V. Petagna of Costa, and Crassina
Britannica of Leach. The North-American form has
been called by Hanley A. latisulca, and by Gould A.
n n data. The variety elliptica is the Venus compressa
of Linne's '
Mantissa Plantarum/ Crassina ovata and
C. depressa of Brown, C. sulcata of Nilsson, A. Gai-
rensis of James Smith, and A. semisulcata of myself,
Loven, Moller, and Philippi, but not of Leach.
2. A. compres'sa *, Montagu.
Venus compressa, Mont. Test. Brit. Suppl. p. 43. t. 26. f. 1. A. compressa,
F. &H. i.
p. 464, pi. xxx. f. 1-3.
Body greyish-white : mantle plain-edged : tabes scarcely
perceptible outside the shell : foot white.
Shell acutely triangular, nearly equilateral, rather convex,
thick, somewhat : glossy sculpture, sometimes only slight, irregular,
and scarcely elevated ridges in the line of growth, but
more commonly also close concentric ribs on the umbonal area ;
the surface is covered, as in the last species,
with liner inter-
stitial striae : colour milk-white beneath the epidermis, which
is of various hues from yellow to chestnut-brown, and is seen
under the microscope to be reticulated lengthwise by innume-
rable rows of punctures :
margins curved in front, obtusely
angular or truncate on the anterior side, with a sharply rounded
point, and sloping or gently curved on the posterior
side to a
blunter point : beaks almost central, considerably recurved towards
the anterior side : lunide and corselet deep and nearly
smooth : ligament cylindrical, of moderate length, yellowishbrown,
not projecting beyond the dorsal line, partly contained
in a groove on the hinge-plate : hinge-line nearly rectangular :
hinge-plate thick and broad, occupying about two-fifths of the
circumference : teeth as in A. sulcata, but the cardinals are
proportionally stronger, and the anterior laterals (especially
that of the left valve) are more : developed inside porcellanous.
slightly nacreous, and minutely tubercled ; margin sharp and
smooth, bordered within by a slight but distinct ridge, forming
* Squeezed together.
p 2