PELECYPODS 449 
sively gathered in the estuaries from Cape May to Cape Cod. Men 
armed with rakes drift about in small boats and fish the sluggish crea- 
tures up out of the mud. They will live for many days out of water if 
kept in acool place. Smaller or immature clams are better for the table, 
since they are not so tough as their elders. A few features of the shell 
of this species are noticeable—the rather prominent umbones directed for- 
ward, the heart-shaped lunule, the external ligament, the concentric sculp- 
turing of growth-lines, the pure-white interior (with occasionally violet 
zones about the 
muscle-secars and 
margin), the three 
stout cardinal teeth, 
the — sharp-angled 
pallial sinus, and the 
ventral margin fine- 
ly crenulated within. 
The greatest length 
is about three inches 
and the height two 
and a half inches, 
but these dimensions 
exceed those of the 
clams usually served 
upon the half-shell. 
V. mercenaria ranges 
into Florida, increas- 
ing in size and bulk 
as it meets the a 
warmer waters of Venus mercenaria, typical form. 
theGulfStream. The 
Floridian form has received the varietal name of mortoni. This massive 
clam sometimes weighs five pounds, and is fully six inches in diameter. 
Aside from its great size and thickness, the characters of the 
shell are wholly those of the smaller Northern form. It is abundant in 
shallow, muddy, brackish bays, and is gathered by men who “tread 
out” the clams, feeling for them in the mud and sand with bare feet. 
The flesh is tough and disagreeably strong, yet the natives appear to 
relish it, especially when it is made into a chowder. . 
V. cancellata. The most abundant species of Venus in Florida, 
particularly near Tampa and on the west side. It preserves all the 
characteristics of the genus, and is decorated with a series of high, 
narrow, concentric ridges, between which are much smaller and more 
numerous radiating riblets. The color is dirty white to light yellow- 
brown without, and white and violet within. There are three cardi- 
nal teeth and no laterals. The lunule is heart-shaped; the pos- 
terior margin is broadened into a wide, concave area into which the 
concentric ridges do not pass. Length one to one and a fourth inches; 
height the same. Sometimes the beaches in Florida will in places be 
banked up with the valves of this very abundant Venus. As they live in 
shallow water upon sandy stations, they are easily dislodged by the 
heavy storms which sometimes sweep that usually placid coast. (Plate 
LXXXII.) 
29 
