O ANOMA. 



slowly widening white belt below the suture; keel 

 white ; 15-17 x 5-5.5 mm., whorls 7-8. 



A. pulchella, no. 16, and var. pulla, no. 16a. 

 aa. Similar, but more slender, 17.5 x 4.66 mm., with 9 

 whorls, the last rib-striate behind. 



A. dohrniana, no. 15. 



&aa. Gray-white, with fine white lines at suture and 



keel; lip pale red, very sinuous; 17x4.7 to 17.6 x 



5.4 mm., 8-Sy 2 whorls. A. sinuata, no. 17. 



"III. Shell robust below, tapering rapidly and conic above, the 



last whorl well rounded, with a narrow and rather low 



basal keel ; last half of the last whorl distinctly, often 



coarsely, rib-striate. 



J.. Shell obesely fusiform, white or reddish below, finely 

 rib-striate throughout, more closely so on last 

 whorl; keel low, cord-like; aperture subvertical, 

 oval, the peristome white, thin, broadly expanded, 

 level and in a plane, the ends converging above; 

 19 x 6.6 mm., whorls 7-7%. A. striata, no. 18. 



*,2. Last whorl hardly narrower than preceding one; 

 spire conic; aperture wide, the lip somewhat sin- 

 uous, its ends distant above; keel narrow and deli- 

 cate. 



a. Spire straightly conic and decidedly slender above; 

 no white sutural band, or only a narrow one; 

 columella hardly truncate; whorls 7%-8; forms 

 from eastern Jamaica (Portland). 



A. nigrescens, no. 20, and varieties. 

 aa. Spire thicker, the truncation wider; forms of cen- 

 tral and western Jamaica. 



A. solida, no. 19, and varieties. 



Group of A. tesselata. 



Tusif orm species with the last whorl rib-striate behind, and 

 tapering to the usually strong basal keel. 



1. A. GOSSEI (Pfeiffer). PI. 17, figs. 10, 11, 12, 13. 



Shell cylindric-tapering, attenuate above, thin, pale cor- 



