MARINE MOLLUSCA OF THE UNITED STATES. 89 



longitudinally furrowed ; spire short, obtuse ; suture strongly 

 impressed, aperture orbicular; umbilicus large, deep. Dull ash- 

 color. 



Height 5, diam. 5 mill. 



Casco Bay, Maine. 



6. M. UNDULATA, Sowerby. Fig. 174. 



M.alacol and Conch. Mag. !., 26. 

 Margarita striata, var. Grmilandica, Moller, IncL Moll. Green. 1843. 

 Turbo incarnatus, Coutbouy, Bost. Journ. Nat. Hist., ii. 98, t. 3, f. 13. 1838. 

 Trochua tumidus, Montagu, Leth. Suev. t. 30, f. 3. 



Shell orbicular, small, smooth and shining; whorls four or 



five, convex, with numerous striag, alternately finer and undulated 



near the sutures by short folds or wrinkles ; umbilicus quite large 



and deep ; aperture nearly circular, very oblique. Uniform red 



of various shades. 



Height 7.5, diam. 10 mill. 



New England. {Eur.) 



Trochus Grcenlajidicus, Chemnitz, 1781, may be this species. 



7. M. HELiciNA, Fabricius. Fig. 175. 



(Turbo.) Fauna Groenl. 1780. 

 Margarita arctica, Leach, Ross' Voj'age. 1819. 

 Turbo inflatus, Totten, Am. Journ. Science, xxvi. 368, f. 5. 1834. 



Shell small, thin, translucent, shining and globular ; whorls 



five, convex, with revolving minute lines on the base ; spire low, 



convex; suture impressed; aperture large, circular and expanded; 



umbilicus large and deep. Pale horn-color. 



Height 5, diam. 6.25 mill. 



New England. 



8. M. CAMPANULATA, Morsc. Fig. 17G. 



Shell small, depressed, orbicular, smooth, shining, translucent ; 

 spire minute, pointed, aperture large, companulate. Light olive 

 or horn-color. 



Length 3.5, diam. 7 mill. 



Neio England. 



9. M. ARGENTATA, Gould. Fig. 177. 



Invert. Mass. Edit. i. 356, f. 174. 1841. 

 Trochus glaucus, Moller, Ind. Moll. Groenl. 1843. 



Shell minute, conical, with an obtuse tip ; pearly white ; whorls 



four, convex, the last slightly angular, covered with fine, crowded, 



revolving lines ; suture deep; aperture circular. 



Height 2.5, diam. 3 mill. 



New England. {Europe.) 



