60 LITTORINIDiE. 



upon the final volution with zones of whitish and cho- 

 colate brown, or sometimes, though very rarely, car- 

 nelian red. Of these bands, there are three light, and 

 three dark ones, commencing with the former, besides 

 the narrow whitish strip that surrounds the pillar ; all, 

 excepting the second darker zone, which is broader than 

 the rest, are almost equally narrow ; occasionally the 

 entire shell is tinged with the darker hue, so that the 

 zones in consequence become obscure ; sometimes, but 

 almost wholly in worn individuals, the colour is lilac or 

 dirty rufous. The closely disposed longitudinal wrinkles 

 of increase are often strongly indicated. There are from 

 three to four volutions that end in a blunt, but very 

 small, and generally white apex, which are only separated 

 by a simple suture, yet are very distinctly defined, owing 

 to their more or less abrupt rise, roundness, and horizontal 

 compression above ; the last character is, however, at times 

 almost obsolete, especially in abraded examples. The 

 rapid increase in size is not confined to the last volution, 

 for the penult turn, likewise, is quickly enlarged. The 

 dorsal length of the body is three times that of the 

 spire (which is occasionally so short, that it does not 

 project beyond the penult turn when viewed dorsally), 

 and is either broadly rounded in the middle, or else is 

 angulated above, and plano-convex in the middle ; the 

 base is short, abrupt in its declination, and usually either 

 straightish or retuse. The aperture, whose length, which 

 at the least is two-thirds that of the entire shell, is greater 

 than its breadth, is suboval and much projecting. The 

 outer lip is almost semicircular, and manifestly recedes 

 towards the base. The pillar-lip is white, solid, rather 

 flat, decidedly broad, not much shelving, scarcely at 

 all oblique, nearly straight at the edge ; it occupies half 



