Family Mactridae — Part 2

Genus SPISULA, Gray

The Dish Shell (S. catilliformis, Conr.) is a fine large clam, with thin, smooth, white shell covered with a wrinkled, gray, horny epidermis. It has the characteristic Mactra shape, with sub-central, elevated beak. The hinge pit is triangular and very large. The pallial line reaches the middle of the shell. Length, 4 to 5 inches. Vancouver Island to Southern California.

Hemphill's Surf Clam (S. Hempbillii, Dall) grows even larger than the dish shells. It is a rare species, found at San Pedro and San Diego. A brown epidermis, much wrinkled at the posterior end, covers the white surface. Except for its narrower anterior end and shallower pallial sinus, this might be mistaken for the preceding species. Length, 6 inches.