46 AMICULA. 



163, t. 13, f. 1-9 ; t. 14, f. 1-6 ; Mai. Rossica i, p. QS.Amicula 

 pallasii H. & A. AD., Gen. Rec. Moll, i, p. 481. CHENU, Manuel, 

 i, p. 383. BALL, Proc. U. S. Nat. Mus. 1878, p. 309. Stimpsoniella 

 pallasii CPR., Bull. Essex Inst. 1873, p. 155. 



Although closely allied to A. vestita, this species differs in the 

 more hairy, thicker girdle, the less exposed tips of the valves, which 

 are smaller and less transverse. The figures do not represent dried 

 specimens. The description is from Middendorff. 



A. AMICULATA Pallas. PL 5, figs. 15, 16. 



This species was described by Pallas from a dried specimen 

 measuring 4 inches in length. Figures 15, 16, are copied from his 

 plate. The following note contains all that is useful in his descrip 

 tion : Valves covered with cartilage, scabrous and subverrucose out- 

 side, the part surrounding the valves being thick, harsh, cartilaginous. 

 The 8 valves are white and very fragile, the first being nearly horse- 

 hoof shaped, crenulated on the front margin; the intermediate 

 valves are shaped as if made of two circular disks, and have a trans- 

 verse obsolete swelling above. The first 7 valves have a pentagonal 

 sharply margined piece (tegmentum), truncated behind, at the 

 angle of the posterior sinus. The 8th valve is angular, as if formed 

 of two pentagons, excavated behind. 



Pallas' figures of the upper surface (26, 27) do not differ from that 

 of A. emersonii except that the exposed portions of the valves are 

 smaller and of a different shape. His figure of the ventral surface 

 (28) shows the gills to extend from the top of the head completely 

 along both sides and uninterruptedly around the tail ! There can 

 be no reasonable question that this is a mistake in the drawingjust 

 as the omission of lateral slits in the intermediate valves is. The 

 gills are probably short, as in vestita and pallasii. 



Kuril Is. (Pallas.) 



Chiton amiculatus PALLAS, Nova Acta Acad. Sci. Imp. Petropo- 

 litanse, ii, p. 235, t. 7, f. 26-30 (1786). GMEL., Syst. Nat. xiii, p. 

 8206. WOOD, Gen. Conch, p. 13. MIDD., Mai. Ross, i, p. 96. 



Not C. amiculatus SOWB., Conch. Illustr., f. 80, nor of Gray, P. Z. S. 

 1847, pp. 65, 69, 169=P. stelleri Midd. Not C. amiculatus WOOD, 

 Index, Test., f. 12, nor of Reeve, Conch. Icon., f. 59=A. vestita 

 Sow. 



? Chamydochiton amiculatus BALL, Proc. U. S. Nat. Mus. 1878, 

 pp. 1, 310. 



