234 AMPHIBULIMA. 



b. Last whorl conspicuously shouldered ; width of shell two- 

 thirds its length or more ; more than three whorls. 



A. patula, p. 234. 



b l . Shell ovate or oblong, spotted, not shouldered; narrower; 

 less than 3 whorls. 



c. Very thin and fragile or flexible ; corneous or 

 greenish, with reddish dots, outer lip regularly arcu- 

 ate, not sinuate ; spire very short: 



St. Vincent, A. tigrina, p. 237; Dominica, A. 



pardvlina, p. 237. 



c 1 . Thin but not fragile or flexible ; outer lip sinuated ; 



colored like the last ; spire slender, between ^ and 



the length of shell ; Dominica, A. browni, p. 238. 



c 2 . Thin, dark horn-colored with very few reddish dots; 



outer lip slightly sinuous ; Montserrat. 



A. rawsonis, p. 239. 



B. Shell regularly Succinea-sh&peA, pellucid, uniform rose corne- 

 ous, the spire projecting, apical 1^ whorls wave-wrinkled, 

 whorls 2|. S.-g. Rhodonyx. A. rubescens, p. 240. 



C. Shell much depressed, the spire very small, scarcely projecting 

 above the vertex of the last whorl, apical whorl smooth ; whorls 

 less than two ; columella with a more or less developed blade- 

 like process ; aperture about as long as the whole shell. S.-g. 

 PeHicula. 



a. Spire a trifle projecting above the posterior border of the 

 lip ; columellar appendage well developed. 



A. appendiculata, p. 241. 



a 1 . Spire sunken or hardly projecting ; columellar appendage 

 less developed. A. depressa, p. 242. 



A. PATULA (Bruguiere). PI. 61, figs. 14-19. 



Shell thin but rather solid, Succinea-like, with the latter half or 

 third of the broad last whorl square-.shouldered, flattened above; the 

 preceding portion not shouldered but steeply sloping, slightly convex. 

 Spire short, conic, red or maroon, rarely yellow ; the last whorl yel- 

 lowish olivaceous, with finely zigzagged or dotted streaks of opaque 

 yellow. Surface with low, irregular wrinkles of growth, and a close, 

 rather fine sculpture of very irregularly anastomosing spiral cords, 

 obliquely descending on the lower portion, the first 1^ whorls finely 



