COLLIER : GENERA AND SECTIONS OF THE PUPININ/E. II3 



Genus Hybocystis Benson, 1859 (humpbacked sack). 

 Shell oval, pupiform. The last whorl but one very large, flat on 

 the ventral face, mouth circular or oval-angular, peristome double, 

 reflected, thick, lip continuous to the upper part, operculum calcare- 

 ous, concave on the outside, with a central nucleus. 

 Distribution : Indo-China. 



Type H. gravida Benson. 



Genus Cataulus L. Pfeiffer, 1851 (spread out). 

 Shell perforated, pupiform, with a pointed apex, at the lower part 

 surrounded by a narrow keel, mouth complete, prolonged at the base 

 by the opening of a trench or gutter, almost circular, peristome dilated 

 at the base, by the keel of the last whorl. Operculum horny, or- 

 bicular, flat, multispiral, separable into several lamellae, nucleus central. 

 Twenty-one species, all in Ceylon, except four from Southern India. 

 Type C. pyramidatus Pfr. 



Section Tortulosa Gray, 1847. 

 Last whorl detached, Nicobar Islands? 



Type T. tortuostis Chemnitz. 



Genus Coptocheilus Gould, 1882 (notch-lip). 

 Shell subperforate, pupiform, with a pointed spire, mouth complete, 

 subcircular, peristome double, the internal sometimes subcanaliculate 

 near to the base of the columella, the internal dilated, operculum 

 horny, multispiral. 



Distribution: Philippines, Borneo, Indo-China. 



Type C. altum Sow. 

 This genus comprises the species from Asia and Malaysia which 

 were formerly placed in the genus Megalomastoma. 

 Genus Megalomastoma (Guilding) Swainson, 1840 

 (large mouth-brim). 

 Shell hardly perforated, oblong turricular or pupiform, apex 

 truncated, opening subcircular, peristome reflected, rather thin, 

 frequently double, operculum horny, circular. 

 Distribution : Antilles. 



Type M. antillarum Sow. 



Section Farcimen Troschel, 1847. 

 Peristome thick, reflected, simple. 



Type M. cylindracetim Chem, 



Sub-genus Tomocyclus (Crosse and Fischer), 1872, 

 Shell turricular, truncated, opening sub-circular, peristome double, 

 the outer one largely dilated, foliaceus, the upper edge interrupted and 

 notched. Distribution: Guatemala. 



Type T. gealei Crosse & Fischer. 



