160 



MALACOZOA. GASTEROPODA. PECTINIBKANCHIAT^, 



fusiform, and whether the species may have been described or 

 not, it is clearly a Tornatella. 



FAMILY V. SIGARETINA. 



Animal with the body oval, convex, slightly spiral, and 

 covered with a shell ; head with a frontal veil ; tentacula 

 large, conical ; eyes at the outer side of their base ; 

 orifice of the branchial cavity an oblique slit, without 

 tube ; two unequal pectinated branchiae ; the mantle 

 with an anterior thin margin ; the orifice of the genera- 

 tive organs near the base of the right tentaculum ; the 

 foot oval or roundish, very large and thick. 



Shell oval or roundish, external or internal, much de- 

 pressed, with a small spire, its aperture very large> 

 without columella. 



GENUS 1. YELUTINA. 



Animal oval, convex above, little spiral ; with the head 

 broad, depressed ; two large tapering tentacula ; eyes 

 sessile at the base of the tentacula externally ; mouth 

 with a short tube ; the mantle double toward the margin ; 

 the foot very large, oval. No operculum. 



Shell ovate or roundish, convex, with a diminutive 

 spire; the aperture extremely large, round or ovate, 

 entire, the margin thin, almost continuous ; no umbili- 

 cus ; the surface covered with epidermis. 



1. Velutina stridta. Striated Velutina. 



Shell roundish-ovate, very thin, brittle, transparent, whitish 

 or pinkish, longitudinally striate, invested with an olivaceous 

 or greyish-yellow epidermis, covered with transverse lamellae 

 in shreds or minute points, so as to present a villous appearance ; 

 spire extremely small, the last turn excessively dilated toward 

 the margin ; aperture roundish-ovate, with the edges reflexed 

 and almost continuous, the inside purple or whitish. Length 

 about eight-twelfths of an inch, breadth nearly the same. 



Animal with two short, tapering, obtuse tentacula, bearing 

 the eyes on a lobe at their base externally ; foot ellipticalj of 

 moderate size ; margin of the mantle plain. 



