MARINE MOLLUSCA OF MADEIRA. 247 



below the tubercles lies a small plain, encircling thread, with a 

 small narrow groove, within which lies a stronger ridge, these 

 two ridges and the furrow between them are pale in colour, 

 sometimes speckled ; within the last of these ridges is a strong 

 furrow, and then the strong ridge forming the/twisted columella; 

 this ridge and the furrow beyond it are stained deep chestnut. 

 Colour varies from dark brown to ruddy chestnut, with a whitish 

 band round the top of each whorl occupying the highest and 

 extending sometimes to the 2nd spiral ridge, with an occasional 

 intrusion to the ridge-tubercles here and there. Rarely the 

 shell, though quite fresh, is pure dead white. Spire rather stumpy 

 for the genus ; the apex, though small, is not drawn out, and 

 ends in a small, rounded, half-immersed tip. Whorls 9 to 9|, 

 rarely 10, nearly flat on the side, of slow and very regular in- 

 crease ; relatively to the axis of the spire the longitudinal ridges 

 run a little transversely. Suture very strongly marked, but its 

 in-girdling appearance is due, not so much to its depth and 

 breadth, as to the way in which the succeeding whorl projects 

 below it. Mouth irregularly rhomboidal, with a small gutter 

 rather than a notch at the point of the pillar. Outer lip straight 

 and sharp, very slightly indented on the base, where it sweeps 

 round with a semicircular curve to the point of the pillar, which 

 leans away from it diverging slightly from the line of the axis. 

 Inner lip has on the pillar a thin but well-marked projecting 

 edge, which thins across the body but recovers its strength at the 

 upper corner near the outer lip. Operculum small, elliptical, 

 thinnish, paucispiral, with a central nucleus; the outer surface 

 is closely scored with fine, curved, radiating lines densely crossed 

 by a minutely microscopic tissue whose lines show the curves of 

 growth.— L. 0-22. B. 0*075. 



Madeira, Porto Santo, Selvagens, Grand Canary. 

 This species is found very abundantly. Mr. McAndrew, 

 however, does not refer to it, nor did I find it in other collections. 

 It is the same as a species sent to me from the Mediterranean 

 as B. lacteum, Phil., but which is, I think, distinct from that 

 species ; the longitudinal spiral and basal threads are the same 

 in number, but in B. incite the apex is smaller and more 

 sunken, being neither so much produced nor so scalar as in that 

 other ; the contour-lines of the shell, too, are distinctly convex, 

 not straight ; the last whorl is more contracted, while the base is 

 attenuated and rounded, not square. 



