282 TR0CHID2E. 



tened above ; minutely wrinkled by the lines of growth, and at its 

 base marked with very fine spiral lines ; suture well impressed ; 

 aperture large, circular, somewhat ex[)anded ; edge 

 ^*^' sharp and simple, a little reflected at the umljilicus, 



J which is large and profound, not bounded by an an- 

 i gular ridge ; operculum horny, multi-spiral. Length, 

 I. one fifth of an inch ; breadth, nearly three tenths of 

 an inch. 



Fig. 543. 



Found abundantly on all our sandy beaches. In 

 some seasons, however, I have looked for them al- 



M.ca,npanula,a.^ ^^^O^^ "^ ^-^"^- "^'l^^ir prOpCF habitat is thc dcCp SCa, 



as they are thrown up alive, on the large leaves of 

 Lamina ria. They were received by Leach and Beck from Green- 

 land, Baffin's Bay, and the Arctic Seas. I have obtained them of a 

 much larger size than is given by any other observer. 



It is a very pretty shell, generally iridescent, or reflecting a me- 

 tallic, l)ronze lustre. It has more the aspect of a land or fresh-water 

 shell than that of a sea-shell. It is not likely to be confounded 

 with any other species except the following. 



I have given this species as the M. arctica, Leach, in accordance 

 with the opinion of Mr. Sowerby, who compared our shells with the 

 authentic specimens in the British Museum. 



I must confess, also, that in comparing the descriptions of M. vul- 

 g-aris and 31. arctica in the " Malac. and Conch. Magazine," and 

 S])ecimens of M. vuli^aris., sent me by Mr. Sowerljy with small speci- 

 mens of the above-described shell, I can perceive no essential dis- 

 tinction, excepting in size ; the first is said to be palish, thc second 

 olivaceous. 



[It is now referred to the Turbo helicinus of Fabricius. 



Margarita argentata. 



Tig. 174*. 



Shell depressed, conical, of a pearly-white color, covered with microscopic, re- 

 volving lines ; umbilicated. 



Margnrita argentata, Gould, Inv. 1st cd. 25fi, fiff. 174*. — Stimpson, Check Lists, 4. 



Shell minute, conical, with an obtuse tip, of a dead pearly-white 

 color; composed of four convex whorls, the last of which is very 



t Fie. 543 represents the allied species M.campannhta, Morse, nsuallv confounded wi;h 

 M. arctica. It appears not to have been recognized by Di*. Gould. — VV. G. B. 



