BULIMULID^E. XI 



Artificial key to genera of Bulimulidse, by shell characters. 

 The Amphibiilimse (see above) are not included in this key. 



Shell Helicoid or trochiform, capable of standing more or less upright 



upon the base. 



a. Aperture conspicuously contracted by teeth or folds. 



b. Aperture turning upward ; shell biconvex, mottled. 



Anostoma, xiv, 109. 

 b l . Aperture oblique, shell transversely oval or trochiform. 



Tomigerus, xiv, 105. 

 a 1 . Aperture toothless. 



b. Apical whorls most minutely, evenly grated (as in pi. 15, f. 

 31); not umbilicate. 



c. Last whorl distorted ; basal lip advanced. 



Zaplagiits, xi, 185. 



c 1 . Last whorl normal; shell trochiform. Oxychona, xi, 181. 

 b 1 . Apical whorls not so sculptured ; shell earthy, dull and 

 opaque, openly umbilicate. 



c. Aperture angular, oblique, the lip simple, discontinu- 

 ous. Platybostryx, x, 129. 

 c 1 . Aperture subhorizontal, the lip flaring, continuous. 



Xenothauma, xiv, 134. 



Shell ovate, oblong or pillar -shaped, '' Bulimoid." 

 a. Apical whorls smooth. 



b. Lip reflexed, often conspicuously thickened ; shell usually 

 solid and rather large. 



c. Aperture angular below, or with sinuous lip ; or the 



lip bears a callous flange. Auris, x, 95. 



c 1 . Aperture broadly rounded below, Plekocheilus, x, 62. 



Porphyrobaphe, xii, 149. 



b 1 . Lip rrflexed ; aperture oblong with parallel margins; size 



small. Anctus, xiv, 36. 



b 2 . Lip acute, not at all expanded ; shell rather large, wholly 



imperforate, the columellar lip completely adnate ; often 



conspicuously colored. Oxystyla, xii, 101. Liguus, xii, 160. 



6 s . Lip acute and simple or expanded ; shells of moderate or 



small size, usually perforate or rimate. JBitlimulus, division 



I, x, 127. Neopetr&us, in part, xi, 163. Leiostracus, xii, 90. 



