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 o£ 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. Earely the 

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

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

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

 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, Grrand 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 £. incile 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. 



