82 AMERICAN MARINE CONCHOLOGY. 



smooth, and covered with a rough, greenish-yellow epidermis; 

 sutural region depressed and sub-channeled ; the spire scarcely 

 prominent above the very large lower whorl, and placed a little to 

 one side ; aperture oblique, semicircular. 



. Length 5, diam. 6 mill. 



New England. 



Genus BISSOA, Fremenville. 



Desmarest, Bull. d. Sc., par la Soc. philom., 7. 1814. 

 Cingula, Fleming, Brit. Anim., 297, 305. 1828. 



The animal has large, slender tentacles^ with eyes on small 

 prominences near their outer bases ; the foot is pointed behind ; 

 the operculigerous lobe has a wing-like process and a filament on 

 each side. 



Universally distributed, but principally in the north temperate 

 zone. They range from high water to one hundred fathoms, but 

 abound most in shallow water, near the shore, on beds of fucus 

 and zostera. 



1. R. MINUTA, Totten. Fig. 153. 



(Turbo.) Anier. Journ. Science, xxvi. 369, f. 7. 1834. 



Shell minute, conic, thin, polished, elevated to an obtuse apex ; 

 whorls five, convex, with very fine transverse striae ; suture dis- 

 tinct, with a round shoulder on the whorl ; aperture oval, entire, 

 rounded at the base, very slightly angular above; lip sharp; lower 

 portion of the pillar-lip slightly recurved, with a loosely attached 

 enamel which rises before an umbilical pit ; operculum horn}', sub- 

 spiral; yellowish-brown, usually covered by a dark green pigment. 



Length 3.75, diam. 1.5 mill. 



Animal dusky -brown ; tentacles, and a line on each side the 



neck, light drab. Very active in movement. 



New England. 



2. R. LATIOR, Mighels and Adams. Fig. 154. 



(Cingula.) Bost. Journ. Nat. Hist., iv. 48, t. 4, f. 22. 1844. 

 Shell minute, ovate-conic, smooth, pale horn -color; whorls more 

 than four, convex ; suture much impressed ; last whorl broad, 

 larger than the rest of the shell ; aperture ovate-orbicular, left 

 margin with a lamina. 



Length 2, diam. 1.25 mill. 



Maine. 



