136 SOLIDULA. 



Synopsis of Genera. 



a. Columella provided with a spiral fold. 



b. Genus SOLID UL A Fischer. Shell compact, solid, ovoid, 

 with short spire ; aperture loDg, narrow above, the col- 

 umella bearing a massive, bifid fold. 



bb. Genus ACTION Montf. Shell compact, with short spire 



and large, ovate body-whorl ; aperture over half the 



length of the shell, narrowed above, the columella bearing 



a single, simple, spiral fold. 



c. S.-g. ACTION Montf. Columella curving regularly into 



the basal lip. 

 cc. S.-g. BJCTAXIS Dall. Columella obliquely truncated at 



base. 



bbb. Genus LEUCOTINA A. Ad. Shell ovate or ovate-tur- 

 rited, the spire produced ; aperture short, generally less 

 than half the shell's length, ovate or oblong ; columella 

 with a small oblique fold. 



aa. Columella with no distinct spiral fold above; shell imperforate 

 or nearly so. 



b. Genus ACT^EONINA Orb. Shell shaped like Adceon, 

 ovate, with elongated aperture, the columella with no 

 fold above, not truncated at base ; whorls more or less 

 angulated below the sutures. 



bb. Genus BULLINA Fer. Shell ovate or oblong, with 

 short spire and long aperture ; columella vertical, trunc- 

 ated at base. 



bbb. Genus OVULACT^EON Dall. Shell Cyprseiform, in- 

 volute, with an apical perforation as in Bulla. Aperture 

 narrow, as long as the shell ; columella without plaits. 

 aaa. Columella without plaits. Umbilicus open ; surface cancellated. 

 b. Genus KLEINELLA A. Ad. Shell ovate, umbilicate, 

 surface cancellated ; spire produced ; aperture elongated, 

 angular behind, produced and entire in front. A doubt- 

 ful member of this family. 



Genus SOLIDULA Fischer de Waldheim, 1807. 



Solidula F. de W., Mus. Demidoff, iii, 1807, p. 226, type Voluta 

 solidula Linn. A. AD., P. Z. S., 1854, p. 60. Dactylus SCHUM., 

 Essai, etc., p. 70, 234, 1817, type Voluta solidula Liune. Buccin- 



