NUBECULA. 



249 



Sub-gen. cylindbella, Swaiuson (not Pfeiff). 



Shell conic-cylindrical, generally grooved; spire elevated, 

 concave. 



cfelatus, A. Adams. 

 Molluccensis, Chem. 

 mucronatus, Bseve. 



scitulus, A. Adams. 

 sulcatus, Hxrass. 



Genus NUBECULA, Klein. 



Shell light, sub-cylindrical ; spire short, but pointed at 

 the summit, whorls slightly coronated ; aperture effuse, 

 emarginate in front ; columella smooth ; outer lip with a 

 wide, but not deep notch at the sutui'e. 



Syn. Rollus, Mont/. Utriculus, ScJmm., not Brown. 

 Tuliparia, Swains. 



Ex, N. tulipa, Linn(BUS, pi. 26, fig. 2. Operculum, 

 N. tulipa, fig. 2, a. Shell, N. geographus, Linneeiis, 

 fig. 2, b. 



M. Quoy observes of this genus that the foot is very 

 large, and not entirely retractile within the shell, as in 

 other members of the family; the anterior marginal 

 groove conceals a large pore, the aperture of an aquife- 

 rous canal ; the tubular veil is fringed at the margin, and 

 can sufficiently dilate itself to admit the tip of the little 

 finger into the orifice. The operculum is small, ungui- 

 culate, and slightly curved. 



Species of Nubecula. 



geographus, Linn. 

 intermedia, Reeve. 



obscura, Humph. 

 tulipa, Linn. 



VOL. I. 



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