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PECTINIDAE 361
row, elongate chondrophore which is flanked on each side by a fluted tooth
and a socket.
Plicatula gibbosa Lamarck Kitten's Paw
North CaroHna to Florida, the Gulf States and West Indies,
Plate 356
About I inch in length, somewhat cat's-paw-shaped. Shell strong,
heavy, with 5 to 7 high ribs which give the valves a wavy, interlocking
margin. Hinge in upper valve with 2 strong, equally sized teeth; lower
attached valve with 2 sockets in the hinge with 2 smaller teeth set rather
close together. Color dirty-white to gray with red-brown or purplish lines
on the ribs. A common intertidal to offshore species.
Family PECTINIDAE
Because of the great number of fossil and living species of scallops and
the almost limitless modifications exhibited by them, there have been no
less than 50 genera and subgenera proposed in this family by various authors.
Doubtlessly, many more will be invented. Most, if not all, of these genera
are closely integrated by connecting species. Workers have a choice of
using the single genus, Pecteji, or employing a genus for nearly every species.
We are arbitrarily employing only six genera Pecte??, Aequipecten, Chla-
772ys, Placopecten, Lyropecteii and Himiites—and we cannot justify these
on biological grounds. It may be noted that we have moved the glassy, thin-
shelled Propeamiisshim from the Pectinidae into a family of its own on
anatomical grounds. This new family refers to what was once called "Amus-
siidae." True Aumsiwn, however, is merely a subgenus of Pecteii connected
to it by a series of species in the Euvola group.
—
Genus Pecten Miiller 1776
Subgenus Pecten s. str.
Pecten diegensis Dall San Diego Scallop
Cordell Bank, California, to Lower California.
Plate 336
2 to 3 inches in size. Right valve convex with 22 or 23 flat-topped ribs
which are generally longitudinally ridged on top. Left valve much flatter,
with 21 to 22 narrow, rounded ribs. Dredged from 10 to 75 fathoms.
Subgenus Patinopecten Dall 1898
Pecten caurinus Gould Giant Pacific Scallop
Wrangell, Alaska, to Humboldt Bay, California.
Plate 29b