North Pacific species of the family Solemyidae — Petrasma pusilla (Gould, 1861); Solemya valvulus Carpenter, 1864; Solemya panamensis Dall, 1908; Petrasma pervernicosa (Kuroda, 1948); Solemya reidi Bernard, 1980; and Solemya tagiri Okutani, Hashimoto & Miura, 2003 — and the type species of subgenera of the genus Solemya Lamarck, 1818, are re-examined. Five species of the genus Solemya are recognized from the North Pacific: Solemya (Solemya) pusilla (Gould, 1861); Solemya (Solemya) valvulus Carpenter, 1864; Solemya (Solemya) tagiri Okutani, Hashimoto & Miura, 2003; Solemya (Petrasma) panamensis Dall, 1908; and Solemya (Petrasma) pervernicosa Kuroda, 1948. The gutless S. reidi from the northeastern Pacific is synonymized with S. pervernicosa from the northwestern Pacific. Solemya pervernicosa was found in the Sea of Okhotsk and in the Sea of Japan near the coast of Sakhalin Island at the 300–800 m depth and was not previously recorded for Russia. A study of the materials of Acharax johnsoni (Dall, 1891) provided additional data on its distribution and ecology in the Pacific Ocean. This species was found in the Sea of Okhotsk (depth 370–1,515 m), as well as in the Monterey Canyon and Peru-Chile Trench (depth 3,040–4,200 m) in cold methane seep areas. The results of a comparative analysis of subgenera and species of the genus Solemya, descriptions of North Pacific species of the genus Solemya, and additional data on the distribution and ecology of A. johnsoni are presented.