CRYPTOCHITON. 49 



The valves are wholly concealed, white or flesh-colored, entirely 

 lacking the outer colored layer (tegmentum) of other Chitons ; their 

 edges are more or less thinned and crenulated by radial striie. 

 Anterior valve (figs. 8, 9) having the apex at the posterior third, 

 and with 4 to 7 slits. Intermediate valves (figs. 12, 13) having the 

 apex near the posterior third ; formed of two large anterior lobes 

 expanded at the sides, and two smaller, narrow posterior lobes. 

 Posterior valve (figs. 10, 11) having the mucro posterior or near the 

 posterior third ; deeply sinused in the rear, and usually having a 

 slit on each side of the sinus. 



Girdle leathery, thick, red, densely covered with countless minute 

 fascicles of vermilion spinelets (pi. 6, fig. 6.) 



Length 15 to over 20 cm. 



Endermo Harhor, south of Jesso, Japan ; Sahalin Island ; Kuril 

 Is.; southern extremity of Kamchatka ; Aleutian Is. ; Alaska and the 

 whole American coast southivard to Monterey and the Santa Barbara 

 Is.; just below tide mark. 



Chiton stelleri Midd., Bull. Acad. Sci. St. Petersb. vi, p. 116 

 (1846). — Chiton, (Cryptochiton) stelleri Midd., Mai. Ross, i, p. 93, 

 t. 1-9 ; Mem. de I'Acad. Imp. Sci. St. Petersb., 6me Ser., vi, p. 101, 

 157, 1849 (full account of anatomy). — Schrenck, Amurl. Moll., 

 p. 271. — Cryptochiton stelleri Gray, Guide Syst. Dist. Moll. B. M., 

 p. 185 (1857).— H. & A. Ad., Gen. Rec. Moll, i, p. 479 ; iii, t. 55, 

 f. 1. — Cpr., Suppl. Rep., etc., Brit. Asso. 1863, p. 648. — Gabb., 

 Palfeontol. Cal. ii, p. 87. — Dkr., Ind. Moll. Mar. Jap., p. 159. — 

 Smith, Ann. Mag. N. H. 1875, xvi, p. 115.— Dall, Proc. U. S. Nat. 

 Mus. 1878, p. 311; p. 299, t. v, f. 44 (dentition). — Cryptochiton 

 stelleri var. violacea Nordmann, Bull. Soc. Imp. des Naturalistes de 

 Moscou, XXXV, 1862, p. 329, t. iv. — Chiton amiculatus Sowb., Conch, 

 Illustr., f. 80, 80bis., and Gray, P. Z. S. 1847, pp. 65, 69, 169. Not 

 of Pallas. — Chiton sitkensis Reeve, Conch. Icon., Chiton, t. 10, f. 

 55; t. 11, f. 55b (1847); not C. sitke^isis Midd. — Chiton chlamys 

 Reeve, I. c, t. II, f. 60. — Chiton californicus Prescott, Amer. 

 Journ. Sci. and Arts (2), xxxviii, p. 185, fig. in text. (Sept., 1864). 

 — ? ? Chiton giganteus Kamtschaticus Tilesius, Mem. de 1 'Acad. St. 

 Petersb. ix, 1824, p. 473, t. 16, f. 1, 2 ; t. 17, f. 3-8 (in part).— 

 Cryptochiton asmus in the Dorpat Collection, teste Midd., Mai. Ross 

 i, p. 40. 



The foot and softer parts of this species are eaten raw by the 

 Aleuts and Indians. 

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