tYRAMlBEtLA. 299 



Subgenus CRYrTOPLOCus, Pictot and Campiche, 1854. 



Shell like Nerinsea, but without eolumellar or labral plaits ; 

 there is one plication on the posterior fiice of the aperture (as in 

 some Cerithiums) ; aperture rounded in front, without channel; 

 axis umbilicated or imperforate ; 7 species, Jurassic and Cre- 

 taceous. Europe. 

 N. MONILIFERA, d'Orb. 



Subgenus Aptyxis, Zittel, 1873. 



Shell turreted, nearly C3'lindrical, imperforate; whorls numer- 

 ous, not embracing; aperture lengthened subquadrangular, 

 without plications, the columella with a fold-like thickening. 



The s3'non3'ms are Pachystylus^ Gemmellaro, 1878, and Aptyxi- 

 ella, Fischer, 1885. The latter name was given because of 

 Aptyxis, Troschel, 1868 — which, however, is a synonym. 

 A. SEXCOSTATA, d'Orb. Jurassic. 



? Genus SOLENISCUS, Meek and Worthen, 1860. 



Shell fusiform, smooth, bod3' -whorl contracted below into a 

 distinct canal, columella with a single oblique plait. 

 S. TYPicus, Meek. ' Carboniferous, Illinois. 



Genus PYRAMIDELLA, Lam., 1799. 

 Typical Group. 

 P. VENTRicosA, Gucriu. PI. 72, figs. 63-65. 



Slightly striated longitudinall3% the last whorl ventricose ; 

 3'ellowish white with irregular light chestnut undulating longi- 

 tudinal stripes, more or less intensified into revolving bands ; 

 cuhimella triplicate. Length, 1-25 inches. 



Vili Inlands, Vanikoro, Singapore. 

 Besides the type, I figure a white variet3'. P. scitula, A. Ad, 

 (fig. 65), is onl3^ a 3'ounger state of this species. 



P. ciN-CTA, Reeve. PI. 72, fig. 66. 



Smooth, white, with a Ijroad central chestnut zone, appearing 

 on the spire whorls; columella triplicate, perforation narrow. 



Length, 20 mill. 



Philippines. 



