MARGARITA. 289 



less flattened, but similarly sculptured, except that the very wide and 

 funnel-shaped umbilicus is destitute of revolving striae, and the lines 

 of growth are here a little stronger. Aperture excessively oblique, 

 with the anterior angle much produced ; lips hardly thickened, and 

 but slightly interrupted at the junction with the body-whorl. Nacre 

 .salmon-color ; externt.l surface pinkish-white, brilliantly pearly 

 where eroded. Alt. "o, diam. '85 in. (Ball.) 



Iliulivk Harbor, Captain's Bay, Unalashka ; larger specimens in 

 the Akutan Pass, 10-60 //»*■; Behring Sea. 



M. vorticifera Dall, Proc. Cal. Acad. Sci. v, 1878, p. 59, t. 2, f. 

 4. — Krausse, Arch, f Naturg. 1885, p. 260. 



This form is closely allied to M. umbilicalis Brod. and 8owb. 



M. AR(4ENTArA Gould. PI. 64, figs. 48, 49. 



Shell small, narrowly umbilicate, globose-depressed, conoidal, 

 thin, subtransparent, corneous or bluish white in color ; surface 

 lusterless, dull, closely marked all over by fine, close-set spiral striae, 

 scarcely visible except under a lens ; spire conoidal, apex minute, 

 blunt ; whorls 4, tumid ; suture deeply impressed ; aperture circular, 

 oblique, outer lip simple, acute, inner lip arcuate, a trifle reflexed ; 

 umbilicus narrow, deep. 



Alt. 21, diam. 3 mill. (American specimens) ; alt. 02, diam. o'2 

 mill. (European specimens.) 



Massachusetts, Englavd, Scandinavia and Northward ; Behring Sea.. 



M. argoitata Gould, Invert. Mass., p. 256, f. 174 (1841).^ — edit. 

 BiNNEY, p. 282, f 544. — M. glaaca Moller Ind. Moll. Graml., p. 

 8 (1842). — Trochus glaucus Moll. Jeffre:ys, Brit. Conch, v (suppl.), 

 p. 202. — Trochus argentatus Gld., Philippi, Conchyl. Cab., p. 285, 

 t. 42, f. 4. — Margarita olivacea Brown, Krause, Arch. f. uaturg. 

 1885, p. 261.— Sars, Moll. Reg. Arct. Norvegite, p. 134, t. 9, f 6.— 

 Trochus olivaceus Brown, 1827, Jeffreys, in Ann. & Mag. N. H. 

 1877, p. 2, 40. — Margarita Aarriso?i?'gHANCOCK, Ann. & Mag. N. H. 

 1846, p. 325. — M. argentata Gld. var. gigantea Leche, Kongl. Sv. 

 Vet., Akad. Handl. Stockholm, p. 43, t. ], f 11. 



I do not know where this shell was described by Brown ; Sars 

 gives no reference nor does Jeffreys. It is easily recognized by the 

 lusterless closely spirally striate surface and small size. Philippi's 

 figures, copied on my pi. 39, figs. 47,48, are incorrect in showing no 

 spiral strise. The var. gigantea of Leche, described from Nova 

 Zembla differs in its large size. Alt. 10-lOA, diam. 10-11 mill. 

 19 



