Alternate name: Atlantic Plate Limpet

Family: Acmaeidae, Limpets view all from this family

Description 7/8-1 3/4" (2.2-4.4 cm) long. Moderately high, with a nearly central apex; base broadly oval. Exterior grayish-white, usually irregularly mottled with reddish-brown in either rays or a netlike pattern; appearing smooth but with many microscopic radial threads and very fine growth lines. Interior shiny, whitish or pale bluish with a large, central, chestnut-brown spot; external mottling often showing through; sometimes a dark, mottled border at edge.

Habitat Abundant on rocks intertidally.

Range On both coasts: Arctic to New York, and to Alaska.

Discussion This is the common large limpet found on the rocky shores of New England and eastern Canada. Like many other limpets, it varies considerably in the height of the shell and in the extent and shape of the internal brown scar. The Latin species name means "like a tortoise shell," probably referring to the shell's mottled appearance.