572 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



EXPLANATION OF PLATES. 



Plate 74. 



Fig. 1. Thais (Nucella) canaliculata Duclos, variety analoga Forbes, unusually swollen 

 and depressed form, from Lituya Bay, Alaska. Cat. No. 220974, U.S.N.M. 

 Alt. 31 mm., p. 568. 



2. Thais {Nucella.) canaliculata Duclos, variety comprcssa Dall, from Monterey, 



California. Cat. No. 60102, U.S.N.M. Alt. 38 mm., p. 569. 



3. Thais (Nucella) canaliculata Duclos, typical form {-\-decemcostata Middendorff) 



Unalashka, Alaska. Cat. No. 220973, U.S.N.M. Alt. 38 mm., p. 567. 



4. Thais (Nucella) canaliculata Duclos, mutation with obsolete sculpture from 



Sitka, Alaska. Cat No 32197, U.S.N.M. Alt. 33 mm., p. 567. 



5. Thais (Nucella) lamellosa Gmelin, variety cymica (smooth mutation) from Port 



Ludlow, Washington. Cat. No. 60125, U.S.N.M. Alt. 38 mm., p. 565. 



6. Thais (Nucella) lamellosa Gmelin, variety /ranciscana Dall, from San Francisco 



Bay. Cat. No. 63909, U.S.N.M. Alt. 50 mm., p. 565. 



7. Thais (Nucella) lamellosa GmeUn, typical form, from oyster reefs, Vancouver 



Island. Cat. No. 63873, U.S.N.M. Alt. 67 mm., p. 563. 



8. Thais (Nucella) lam,ellosa Gmelin, variety hormica Dall, from inner harbor of 



Sitka, Alaska. Cat. No. 88862, U.S.N.M. Alt. 53 mm., p. 565. 



Plate 75. 



Fig. 1. Thais (Nucella) emarginata Duclos, variety ostrina Gould, from Monterey, 

 California. Cat. No. 32176, U.S.N.M. Alt. 36 mm., p. 570. 



2. Thais (Nucella) emarginata, typical short and stout form, from Lituya Bay, 



Alaska. Cat. No. 220975, U.S.N.M. Alt. 30 mm., p. 569. 



3. Thais (Nucella) emarginata, elevated form, from Monterey, CaUfomia. Cat. 



No. 32179, U.S.N.M. Alt. 33 mm., p. 569. 



4. Thais (Nucella) lima Martyn, typical form, smooth mutation, from Kadiak 



Island, Alaska. Cat. No. 60105, U.S.N.M. Alt. 33 mm., p. 566. 



5. Thais (Nucella) lima, abnormally elevated mutation, from Unalaska, Alaska. 



Cat. No. 60084, U.S.N.M. Alt. 49 mm., p. 566. 



6. Thais (Nucella) lima, normal form, heavy mutation, from PortMoller, Alaska. 



Cat. No. 22097G, U.S.N.M. Alt. 40 mm., p. 566. 



