652 PROCEEDINGS OF THE ACADEMY OF [DeC, 



the lowest on the last two whorls; base with nine keels, nearly 

 equally spaced and nearly equal, except the first, which shows a slight 

 tendency to tuberculation; interspaces rather broader than the 

 keels; last two whorls with twenty vertical ribs, the preceding with 

 eighteen; apex eroded, with about four whorls remaining; upper 

 whorls moderately convex, the last, with the base, well rounded; 

 sutures well marked. Aperture slightly oblique, broadly ovate, 

 whitish, shading to yellowish on the columella, smooth, except on 

 the parietal wall, over most of which the epidermis and basal keels 

 extend for more than a whole turn within the shell, leaving a narrow 

 space above occupied by a callus carrying a shallow posterior canal; 

 outer and lower lips, though somewhat broken, seeming to be mod- 

 erately sharp and crenulated by the external sculpture; columella 

 very concave, scarcely revolute, somewhat flattened externally, the 

 surface thus formed extending to the effuse lower lip. 



Estimated alt, 46, actual alt. 41, greatest diam. 28, length of 

 aperture 20.5 mm. 



A single dead specimen of this species was taken in the Igarape de 

 Paituna near Monte Alegre, Fazendo Ponto. 



Doryssa starksi n. sp. PI. XXV, figs. 5, 6, 13, 14. 



Shell varying from broadly ovate conic to rather narrowly conic, 

 very solid and heavy and with a very dense epidermis; color varying 

 from dark olive-brown to nearly black ; sculpture varying, some 

 specimens showing both strong, nearly vertical to slightly retractive 

 ribs and spiral keels throughout the whole shell, others having weak 

 vertical ribs only on the last whorl and spiral keels which become 

 nearly obsolete on the upper whorls; the most globose specimen 

 (type) with the vertical ribs more marked than the spiral keels. 

 Apex eroded in all specimens, the remaining whorls of the type 3|, 

 scarcely convex; last whorl with eleven very strong vertical ribs, 

 the penultimate with fifteen, the next with sixteen, the ribs weakening 

 towards the apex; spiral keels five, with a sixth forming in some 

 specimens in the lower sutures or by intercalation; well-marked 

 growth lines and very distinct incised spiral striae over the whole 

 shell, the latter visible under a strong glass; intersections of the 

 ribs and keels producing tubercles which are slightly produced spi- 

 rally; tubercles of the third, fourth, and sometimes the fifth keels of 

 the last whorl generally much enlarged, producing a subangulation 

 at the periphery; base moderately rounded, showing faint continua- 

 tions of the vertical ribs and marked by seven or eight subequal 

 keels with broader interspaces, the interspaces narrowing slightly 



