282 TROCHID^. 



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



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



aperture large, circular, somewhat expanded ; edge 



Fig. 542. sharp and simple, a little reflected at the umbilicus, 



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



J- gular ridge ; operculum horny, multi-sjjiral. Length, 



M.heiicina. ouc fifth of an iucli ; breadth, nearly three tenths of 



an inch. 



Fig. 543. 



Found abundantly on all our sandy beaches. In 

 |>) >-]— I some seasons, however, I have looked for them al- 



M.ca,npanulataA ^"^^^^ "^ '■'^"^- ^^^"^''' P^'^pCr habitat is thc dcCp SCa, 



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

 Laminaria. 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, bronze 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- 

 garis and M. arctka in the " Malac. and Conch. Magazine," and 

 specimens of M. viil^-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 ; thc first is said to be palish, the second 

 olivaceous. 



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



Margarita argentata. 



Fig. 174*. 



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

 volving lines ; unibilicatcd. • 



Marfjarita argmtata, Gould, Inv. 1st ed. 2.56, fig. 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 Fiji-. •543 represents the allied species ]\f. campaniildta, Morse, nsiiallv coiifoinidcd wi;h 

 M. arctica. It apj^ears not to have becu recognized by Dr. Gould. — W. G. B. 



