Shell oval, apex pointing forward, posterior slope long, convex, anterior slope short. Sculptured with strong, rounded ribs, usually nodulous, but sometimes obsolete. Whitish, with stripes and zigzags of blackish-brown, or olive-green variegated and speckled with white. Margin crenated by the ribs. Inside white or stained with yellowish-brown, with a large central deep brown area, rarely absent; border articulated black and gray.

Shell. Medium to high profile; apex positioned in the anterior third of shell. Anterior slope straight; all other slopes convex. Sculpture of radial riblets, sometimes obscure on larger specimens (20 mm). Color olive-green with fine white tessellations; large, oval white markings on anterior and anterolateral surfaces. Apex erodes to brown. Interior margin wide, dark; intermediate area white; interior stain brown, irregular. Length, 10-50 mm.
Animal. Lacks pigmentation.
Radula. First lateral plates closely set at anterior edge of ribbon segment, elongate, blunt distally; second lateral teeth posterior and lateral of first lateral teeth, blunt distally. Third lateral teeth lateral of second lateral teeth, wedge-High and middle intertidal, in caves, cracks and crevices. Also under larger rocks in middle intertidal.

Much variation:
Forma digitalis:
This is the most usual form found north of San Francisco Bay. It is dull, lusterless, whitish, with stripes and zigzags of blackish-brown. The apex is usually decidedly anterior and elevated ; the front ribs are obsolete, the posterior ribs strong, rounded, often uneven. Inside margin conspicuously tessellated; central area generally dark and rather narrow. This is the oregona of authors, and probably radiata of Eschscholtz. It resembles the striped variety of the Chilian A. ceciliana so closely that it would be absolutely impossible to separate a mixed lot.
Forma umbonata:
The prevalent form southward of San Francisco is an oval shell with rather spreading sides, the ribs narrow, interspaces wide and flat. Color dark olive to blackish, closely flecked with fine white dots, and usually having coarse white dashes also. This variety becomes at times wholly free from ribs.
Another variety, typically equally distinct, but nameless, is found rom San Francisco to San Diego. It is a small shell resembling somewhat A. patina. There are no riblets. The surface is lusterless, white, with numerous, rather narrow, radiating brown stripes, often broken or abruptly divaricating. Inside generally without a central dark area.

Lottia persona is one of the most abundant limpets in San Francisco Bay. However, it is seldom considered so because of its cryptic habits. Lottia persona is a nocturnal species and during daylight spends its time in crevices and cracks. This type of habitat is readily available in the numerous breakwaters and riprap areas throughout the Bay. Larger specimens (>30 mm) appear to be less sensitive to light and may be found exposed in the extreme high intertidal. Before about 1930 references to "Acmaea persona" refer to Lottia digitalis, as the 2 species were not recognized as distinct until about this time.

Shumagin Islands, Alaska (55°N, 160°W) to Morro Bay, California (35°3O0 (McLean, 1966:101). San Francisco Bay: San Francisco County—Land's End, Fort Point, St. Francis Yacht Club Breakwater, Aquatic Park, Alcatraz Island, Angel Island, Yerba Buena Island; Marin County—Sausalito Breakwater, Tiburon Point, Peninsula Point; Alameda County—Fleming Point, Berkeley Marina, Alameda Naval Air Station Breakwater.