Subgenus (Portlandia) O. A. L. Morch, 1857

(3-6-1-0-3-7-2-85-2-0-0-0-0)
Ref. Bernard, 1984 p 16
Wagner, 1984 p 48

arctica (J. E. Gray, 1824)
(3-6-1-0-3-7-2-85-2-1-0-0-0)
Arctic Nutclam
Ref. Amer. Fish. Soc., 1988 p 22
Syn. Leda (Portlandia) collinsoni W. H. Dall, 1919;
Nucula (Nucula) arctica J. E. Gray, 1824
Ref. Bernard, 1984 p 16 bw

dalli A. Krause, 1885
(3-6-1-0-3-7-2-85-2-2-0-0-0)
Dall Nutclam
Ref. Amer. Fish. Soc., 1988 p 22