FERUSSACIA. 215 



whorls and small ovate toothless aperture ; outer lip not arched 

 or sinuous, thickened within; parietal callus thin; columella 

 slightly sinuous, not truncate. Europe, Asia, North America. 



HOHENWARTIANA Bgt. Small, slender, fusiform, fragile 

 and clear corneous, with very slightly convex whorls ; aperture 

 piriform, toothless; outer lip thin; columelia tapering or a 

 little excised below, not truncate. Soft anatomy unknown. 

 Europe. 



C^ECILIOIDES Herrm. Very small and slender, with narrow 

 spire and obtuse apex, thin, fragile and corneous; aperture 

 ovate or lanceolate; outer lip thin, arcuate, columella usually 

 truncate or subtruncate at base. (See Vol. XX). 



COILOSTELE Bens. Minute, cylindric-turrite, apex obtuse, 

 corneous, thin, the internal partitions absorbed in adults. 

 Aperture small, ovate, oblique, toothless; columella not trun- 

 cate. Aden, Spain, Mexico. 



GLESSULA Martens. Ovate-conic with more or less turrite 

 spire and convex whorls; aperture ovate, toothless; columella 

 short, very concave, and strongly truncate at the base ; outer 

 lip thin. Size usually larger than any of the preceding. 

 Oriental region. (See Vol. XX). 



Genus FERUSSACIA Risso. 



Ferryjsacia Risso, Hist. Nat. Eur. Merid. iv, 1826, p. 80. 

 Not Ferusmcia Leufroy, Ann. Sci. Nat. xv, 1828, p. 403 (= 

 Ferussina Grat. 1827 ,=Strophostoma Desh. 1828). Ferus- 

 sacia BOURGUIGNAT, Amenites Malacologiques, in Revue et 

 Mag. de Zoologie 1856, p. 327. 



Shell rather small (usually 6-12 mm. long), varying from 

 acutely ovate to cylindric-oblong ; usually somewhat opaque, 

 glossy, composed of 5 to 8 flat whorls parted by a linear, su- 

 perficial suture, usually bordered by transparence below. The 

 aperture is ovate or piriform, more than half the length of 

 the shell; the outer lip obtuse; columella having a convex 

 fold, or rarely truncate at the base. Foot having pedal 

 grooves and a caudal mucus gland, behind which the tail is 

 truncate. Teeth all tricuspid, the centrals very small. Jaw 

 finely plaited, genitalia simple. 



