PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 311 



tfreat Cryptochiton Stelleri of modern authors. Some specimens of Stel- 

 leri in the Berlin Museum are marked amiculatus on very ancient labels, 

 so there can be little doubt that the two species were confounded by the 

 earlier authors. 



Genus CRYPTOCHITON Midd. and Gray. 



Midd. Mai. Ross, i, pp. 1-96, pi. 1-9, 1847. Type C. stelleri Midd.— Gray, P. Z. S. 

 1847, pp. 65, 69, 169 ; Guide, p. 185, 1857. 



Yalvae omnino in zona iminersse; laminae insertionis rude mopa- 

 loideae; lam. sutur. tain postice quam antice junctae, postice trisiuuata) ; 

 zona minutissime fasciculatim pilosa ; branchiae ambientes. 



This genus was simultaneously described under the same name by 

 Gray and Middendorf, apparently without knowledge of each other's 

 labors, and both having the same species in view, though Gray errone- 

 ously supposed his type to be the C. amiculatus of Pallas, and called it 

 by that name ; his diagnosis and synonymy, however, showing that he 

 really referred to C. Stelleri. 



It appears probable, from some of Pallas 7 specimens examined by me 

 in the Berlin Museum, that he included this species with the amiculatus 

 in his distribution, and, in fact, unless carefully examined, almost any 

 one might do the same. 



Cryptochiton Stelleri. 



Chiton Stelleri Midd. Bull. Acad. Sci. St. Pdtersb. vi, p. 116, 1846. 



Chiton {Cryptochiton) Stelleri Midd. Mai. Eoss. i, p. 93, t. i-ix, 1847; Mom. 



de l'Acad. Imp. Sci. St. Petersb. 6me ser. vi, p. 101, 157, 1849.— Schrenck, 



Amur-Land Moll. p. 271, 1867. 

 Chiton amiculatus Sowerby (not Pallas), Conch. 111. f. 80, 80 bis, 1839.— Gray, 



P. Z. S. 1847, pp. 65, 69, 169. 

 Chiton sitkensis Reeve, Conch. Icon. Chiton, pi. x, f. 55, 55 b, 1847. (Not C. 



sitlcensis Midd. ) 



Chiton chlamys Reeve, 1. c. pi. xi, f. 60, 1847 (from type, Cpr.). 



Cryptochiton Stelleri Gray, Guide, p. 185, 1857. — H. & A. Adams, Gen. Roc. 



Moll, i, p. 479, iii, pi. iv, f. 1, la, 1854.— Carpenter, Suppl. Rep. Brit, As. 



1863, p. 648. 



(Patella} longw Eondeletii auf Kurilisch Kcru, Steller, Besehreib. Kamtscli, 

 p. 177, 1774.) 



C. t. intusj v. post, mopaloidea, mucrone obtuso ad posticam trien- 

 tem; sinu caudali alto, lato; fissuris utr. hit. una, subposticis, con 

 spicuis; lam. sut. anticis latioribus, junctis, sinu jugali alto, modico, 

 subplanato; v. ant. mucrone ad quartern partem posticam, normaliter 

 utr. lat. 1- et ant. 3- (id est omnino 5-, sed intcrdum 4-6-, sen 7 ) flssatfi ; 

 lam. sut. posticis longis, lateraliter conspicne sinuatis, medio junctis, 

 sinu postico altissiino, pyrainidali, frustratoj v. centr. inner, ad quintain 

 partem posticam; baud seu interdum 1-fiss. ; lain. lat. ct sutur. ant. 

 baud separatis, sinu jugali angustiore, altissiino, i ireful a liter arcuato, 



