C2 AMERICAN MARINE CONCIIOLOOY. 



Color wliitish, with two bands of pale rufous spots and a rufous 

 band near the suture. 



Southern Coast. 



A doubtful species ; has not been recentl}^ detected. 



Genus MARSENINA, Gray. 



1. M. PERSPicuA, Linnoeus. Fig. lOT. 



{Helix.) Syst. Nat., edit. xii. 1260. 1-767. 

 Ilelix Jialiotoidea, Linn. Syst. Nat., edit. xii. 1250. 1757. 

 Sigaretus haliotoideus, Laiuarclc, Anini. s. Vert., vi. 208. 1823. 

 Oxynoe glabra, Couthouy, Bost. Jouru. Nat. Hist., ii. 90, t. 3, f. 16. 1838. 



iShall small, obliquely ovate, pellucid, white, compressed, 

 smooth; aperture very large; whorls two. 

 Length 12.5, diam. 10 mill. 



Coast of Massachusetts ; Nortliern Europe. 



Genus VELUTINA, Blainville. 

 Malacol. 4G8. 1825. 



1. V. LAEVIGATA, Linnreus. Fig. 108. 



{Helix.) Syst. Nat., edit. xii. 1250. 1767. 

 Helix haliotoidea, Fabricius, Fauna Grcenl. Nq. 387. 1780. 

 Bulla velutina, Miiller, Zool. Dan. iii. t. 101, f. 1-4. 1789. 

 Velutina capuloidea, Blainville, Malacol. t. 42, f. 4. 1825. 

 Velutina rupicola, Conrad. Journ. Pbila. Acad. Nat. Sci., vi. 266. 1831. 



Shell small oval, very thin and fragile. Whorls three ; the 

 bod^'-whorl with faint concentric striiE ; spire slightly raisetl, 

 smooth at the apex. Aperture regularly oval. Epidermis, when 

 not abraded, thick and raised, more conspicuous on the concentric 

 lines. Dusk}^ brown with numerous revolving raised rufous lines. 



Length 7.5, diam. 6.25 mill. 



Cape Cod, Massachusetts, northrcards (Eur.). 



This shell is extremely fragile, seeming to consist principally 

 of epidermis. European specimens attain larger dimensions and 

 are more solid. 



2. V. zoNATA, Gould. Fig. 109. 



Invert. Mass., edit. i. 242, f. 160. 1827. 

 Shell small, ovate, moderately thin ; spire not raised. Whorls 

 three; the two upper ones scarcely distinct; suture deepl}'- im- 

 pressed, striated with revolving lines and superficial concentric 

 furrows. Aperture regularly oval; lip expanded, exceedingly 



