CLASS PELECYPODA 
91 
Lyonsia pugetensis Dali, 1913. 
Plate 28, fig. 2. 
Proc. U. S. N. M., 45 :595. Rep. Puget Sound Shells; pi. 2, fig. 3. 
Shell large, thin, pearly under a thin, olivaceous, gray periostracum 
which is covered with fine radial lines to which fine sand adheres strongly, 
so that an attempt to remove the sand destroys the greater part of the 
periostracum; the shell is slightly inequivalve and very inequilateral, the 
anterior end being much the shorter; the periostracum projects over the 
shelly margin; the anterior end is evenly rounded, the posterior rostrate, 
the beaks not conspicuous; the base is convexly arcuate in the middle, but 
is rapidly attenuated toward the rostrum, which is terminally truncated; 
interior pearly, pallial area relatively small within the somewhat irregular 
unsinuated pallial line; hinge edentulous with a small narrow lithodesma. 
Length of shell, 36; of anterior portion, 15 ; height at beaks, 17; maximum 
diameter, 10 mm. (Dali.) 
Type in U. S. N. M., No. 249966. Type locality, Coast of Wash¬ 
ington. 
Range. Chignik Bay, Alaska, to Puget Sound. 
Lyonsia californica Conrad, 1837. 
Plate 27, fig. 3. 
Jour. Acad. Nat. Sci. Phila., 7:248; pi. 19, fig. 20. 
Shell produced, equivalve; posterior side narrowed, truncated at the 
extremity; umbo inflated; epidermis with radiating striae. Length, 1 
inches. (Conrad.) 
Type in U. S. N. M., No. 253111. Type locality, near Santa Barbara, 
California. 
Range. Puget Sound to Todos Santos Bay, Lower California. 
Lyonsia californica haroldi Dali, 1915. 
Proc. U. S. N. M., 49 :453. 
Shell with nearly cylindrical form without arcuation. (Dali.) 
Type in U. S. N. M. Type locality, San Francisco Bay, California. 
Range. Known only from the type locality. 
Lyonsia (californica var. ?) nesiotes Dali, 1915. 
Proc. U. S. N. M., 49:453. 
Shell very thin, small, translucent; with the beaks very close to the 
anterior end; it may prove to be distinct. (Dali.) 
Type in U. S. N. M., No. 206410. Type locality, Catalina Island, 
California. 
Range. Catalina Island, California; Coronado Islands and Magda¬ 
lena Bay, Lower California. 
HOiJLVN 
