186 DRYM^US-ZAPLAGIUS. 



b. Base flattened; solid, with wide dark bands; outer 

 lip inserted at top of penultimate whorl, having a 

 conspicuous external " spout " ; surface finely mal- 

 leated throughout, navieula, p. 186. 



b f . Base convex ; white ; concave and with oblong- 

 squarish impressions above and below the project- 

 ing keel, the outer lip inserted at apex, 



involuttu, p. 187. 



b". Base convex ; banded and maculate, coarsely mal- 



leate above keel and on base; outer lip inserted above 



middle of penultimate whorl, uranops, p. 188. 



a'. Outer lip inserted well below suture on the last whorl ; 



basal lip slanting. 



b. Banded and maculated, the base flat, alt. nearly as 

 great as diameter, lateralis, p.188. 



II. Altitude of the oblong-conic shell greatly exceeding the diameter ; 

 mouth higher than wide. 



a. Last whorl compressed laterally, base squarely truncated, 



the aperture rounded or truncate below, aurismuris, p. 191. 



a'. Last whorl obliquely truncate below, aperture produced 



basally, aurisleporis, p. 189. 



D. NAVICULA (Wagner). PI. 27, figs. 16, 17, 18, 19 ; pi. 25, fig. 62. 



Shell obliquely conic with flat base, and long, semicircularly 

 curved rimation ; solid ; slightly brown- or yellow-tinted white, 

 becoming pink on the spire, with two broad spiral zones of black- 

 chestnut, the upper one ascending the spire, and on the base a sigmoid 

 chestnut stripe running near and parallel to the umbilical rimation 

 and basal lip, with some faint brown circular lines, sometimes hav- 

 ing a broad dark basal band (fig. 19). Surface hardly shining,, 

 slightly striated, with faint, fine and close spiral striae in places, the 

 last whorl closely malleated throughout. Whorls 6, the earliest If 

 sculptured as usual in the genus, apex white; last whorl convex 

 above, angular at base, its last third strongly ascending. 



Aperture oblique, triangular, effuse at the produced outer angle; 

 peristome broadly expanded, reflexed, white, the upper lip sinuate,, 

 inserted at the top of the penultimate whorl; basal lip horizontal, 

 straightened. 



Alt. 23, diam. 3H mill. 



Alt. 16, diam. 27* mill. 



Province of Bahia, Brazil.. 



