Lithophaga abbotti: Lithophaga abbotti, new species
Kino Bay, Sonora, tidal zone (1932). Type 11390, Lowe collection; para-types, San Diego Society of Natural History and Academy of Natural Sciences of Philadelphia.
Shell cylindrical, thin, posteriorly obtusely rounded, anteriorly tending to subangulation above, evenly rounded below; growth lines are plainly visible under the shining light brown epidermis. The whole shell is covered with a lime incrustation somewhat ruffled in the central portion of both valves. The anterior end is less attenuated than either L. attenuata Desh. or L. aristata Hanley. Diameter 62.5 mm., altitude 19.5 mm.
The type and several additional specimens were obtained in a mass of worm tubes, coralline growths and lime incrustations on a tidal bar a mile or more back in the estuary at Kino Bay, January, 1932. A single specimen was taken in 1933 at San Felipe on the western side of the Gulf of California.
In the U. S. National Museum is a single specimen (#381411) of the above species marked from San Lucas Island, Costa Rica, which measures as follows: length 40.4 mm., width 12.5 mm. This largest of our West Coast Lithophaga is named in honor of Clinton G. Abbott. Director of the Natural History Museum, San Diego, California.