yoTJ'Js ox i'yiiamidellii).t:—I)ALL and bartscii. 82^)- 



PYRAMIDELLA ( ACTiEOPYRAMIS) CASTA A. Adams. 

 I'late XIX, lig. 4. 



Monoptygnia caatn A. Adams, Proc. Zool. Soc, 1851, j). 228; iilso in Sowerliy 

 Thes., 1S54, p. 81S, pi. (-i.x.xii, lig. 22. 



Shell elongate-conic, moderately stout, yollowish-white. Nuclear 

 whorls small, almost completely immersed in the first post-miclear 

 whorl; the periphery of the last volution only is visible, and this 

 appears at right angles to the axis of the later whorls. Post-nuclear 

 whorls moderatel}^ rounded, marked by mere lines of growth and 

 many broad, deepl}^ incised spiral channels, which are almost equal in 

 ])readth to the raised spaces bounded b}' them. These channels are 

 crossed by numerous small axial riblets, which render the edges of the 

 spiral raised hands somewhat crenulate. The spiral raised bands are 

 faintly spirally striated. Ten of these incised channels appear between 

 the sutures on the third and fourth, and eleven on the sixth and the 

 penultimate whorl, The posterior channel is usually a little wider 

 than the rest. Periphery and base of the last whorl well rounded, the 

 latter sculptured like the spaces between the sutures, having twelve 

 incised channels. Aperture suboval, posterior angle acute, outer lip 

 wavy, rather strong and opaque; columella slender, curved and twisted 

 with an ot)lique, obsolete fold near its insertion, parietal wall without 

 marked callus. 



There are two specimens among the Berlin material, both belonging 

 to the Ptetel collection and both from Japan. The largest, the one 

 described above, has eight post-nuclear whorls and measures: long. 

 11,3 mm.; diam. -1.1 nmi. The other has seven and one-half post- 

 nuclear whorls and measures: long. 10.5 mm.; diam. 3.9 mm. 



This species in general outline recalls P. {A.) fulva^ but is much 

 smaller, has many more incised spiral channels, and is white in color. 



PYRAMIDELLA (ACTiEOPYRAMIS) LAUTA A. Adams. 



Plate XIX, fig. 5. 



Monoptygma laxda A. Adams, Proc. Zool. Soc, 1851, p. 222; al8o in Bowerby 

 Thes., 1854, p. 817, pi. clxxii, fig. 20. 



Shell broadly elongate-conic, subturrited, rather stout, milk-white. 

 Nuclear whorls small, almost completely immersed in the first post- 

 nuclear whorl, only the tilted edge of two volutions is apparent, which 

 indicates that the axis of nuclear whorls is at right angles to the axis 

 of the later ones. Post-nuclear whorls inflated, strongly shouldered 

 at the summit, decidedly rounded, marked ])y many weak, irregular 

 axial riblets and very strong, broad, angular, incised, spiral channels, 

 which are crossed by many more or less regularly spaced and sub- 

 equall}' developed backward slanting axial riblets. These riblets 



