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OSTREIDAE 37 3
similar to the Pacific Coast species. Inch-long, brownish specimens are fpund
in the crevices of coral boulders below low-water mark to several fathoms.
Larger, more whitish specimens are found clinging to iron wrecks. Moder-
ately common. P, decipiens Philippi. See plate 38b.
SuperfavTily OSTREACEA
Family OSTREIDAE
Genus Ostrea Linne 1758
This genus used to include all of the oysters, but today several valid
genera are recognized, so that only three American species are included in
true Ostrea. These are O. eqiiestris Say and O. permolUs Sowerby from the
Atlantic Coast and O. hirida Carpenter from the Pacific Coast. The Euro-
pean oyster, O. ediiUs Linne is also in this group. All of these oysters are
relatively small. The eggs are fertilized and developed within the mantle
chamber and gills. Usually around one million eggs are produced at one
spawning. The prodissoconch hinge is long, the valves symmetrical. In the
adults, the muscle scar is near the center of the shell and is not colored.
Ostrea equestris Say Crested Oyster
North Carolina, Florida, the Gulf States and West Indies.
Plate 28c
I to 2 inches in length, more or less oval, and with raised margins which
are crenulated. The attached valve has a flat interior with a rather high, ver-
tical margin on one side. Interior dull grayish with a greenish or opalescentbrown
stain. Margin sometimes stained a weak-violet. Not very abundant
except in some Florida bays. It lives in water that is much saltier than that
in which virginica lives. Also named spreta Orbigny. O. cristata Born is
quite different and is limited to South America.
Ostrea pons Linne
Florida, Louisiana and the West Indies.
'Coon Oyster
Plate 28d
I to 2 inches in size. The radial plicate sculpture and corresponding
sharply folded valve margins are characteristic of this intertidal species. Inner
margins of valves closely dotted with minute pimples for nearly the entire
circumference of the valves. Muscle scars located well up toward the hinge.
Beaks somewhat curved. Interior translucent-white, exterior usually purplish
red. Frequently elongate and attached to stems of trees by a series of clasp-
ing projections of the shell, but may be also oval in shape. O. rubella and
O. limacella Lamarck are this species. O. jolimn Linne is a Philippine species.