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454 American Seashells
fined radial ridges near the center of the valves. Common in mud in cold
waters offshore.
Vanomya ampla Dall Ample Rough Mya
Aleutian Islands to Puget Sound, Washington.
2 to 3 inches in length. A peculiarly distorted, heavy shell which is
much gaping at both ends. Anterior end crudely pointed; posterior broadly
truncate. With 3 to 6 depressed scars on the white interior. Exterior con-
centrically roughened, ash-white in color, with a border of thick, irregular,
black periostracum. Hinge without definite teeth. Uncommon offshore in
cold water.
Genus Panope Menard 1807
Panope generosa Gould Geoduck
(Goo-ee-duck)
Alaska to the Gulf of California.
7 to 9 inches in length. Inflated, sHghtly elongate and rather thick-
shelled. Gaping at both ends. Coarse, concentric, wavy sculpture present,
especially noticeable near the small, central, depressed beaks. Periostracum
thin and yellowish. Exterior of shell dirty-white to cream; interior semiglossy
and white. Hinge with a single, large, horizontal thickening. The
2 long, united siphons of the animal are half the weight of the entire clam.
Common in mud 2 or 3 feet deep in the northwestern states. Edible but
tough. Freaks have been named soJida Dall, globosa Dall and taeiiiata Dall.
For an interesting and well-illustrated account of this species, see Natural
History Magazine (N.Y.), April, 1948, on "We Go Gooeyducking" by the
Milnes.
Panope bitriincata Conrad from North Carolina to Florida is 5 to 6
inches in length and resembles the Pacific geoduck. Dead valves are rarely
found, and I have never seen a live specimen. Possibly extinct.
Superjamily MYACEA
Family MYACIDAE
Genus Mya Linne 1758
These are the soft-shell or "steamer" clams which are so popular in New
England. The valves are slightly unequal in size and have a large posterior
gape. Resilium internal, placed posterior to the beaks and attached in the
left valve to a horizontally projecting chondrophore.