312 COCHLICOPA. 



Una octona; C&cilioides acicula; Ferussacia folliculus and 

 Cochlicopa lubrica, besides a number of undescribed forms. 

 Ferussac recognized two sections, Polyphemge and Styloides; 

 the latter term was used in a generic sense by Fitzinger, some 

 years later, while Ferussac 's inclusion of Columna as a 

 synonym, caused some Italian authors to use that name for 

 C. lubrica and its allies. In 1826 Risso redefined Cochlicopa, 

 retaining the single species lubrica therein, and formed new 

 genera for various 'other of Ferussac 's species. This fixed 

 the significance of Cochlicopa several years before any other 

 name was published for the group. 



Dr. William Elfort Leach proposed the genus Zua in a 

 work on the shells of Great Britain, in course of printing 

 at the time of his death in 1820, but not finally published un- 

 til 1852. Meantime Turton had mentioned "Zua lubrica 

 Leach" in his synonymy of Bulimus lubricus (Manual Shells 

 Brit. Is., 1831, p. 82), and Dr. Gray had introduced the 

 genus in his edition of Turton 's Manual, 1840, p. 187. Var- 

 ious writers have adopted Zua as a genus, erroneously dating 

 it 1820. Its appearance in a published work dates from 1831. 



1. C. LUBRICA (Miiller). PI. 49, figs. 33, 34, 35. 



Shell oblong, the spire gradually tapering to an obtuse 

 apex; thin, smooth, yellowish corneous, subtransparent and 

 very glossy. Whorls 5 l / 2 to 6, moderately convex. Aperture 

 subvertical, ovate, toothless ; outer lip evenly arcuate, obtuse, 

 bordered with yellow T or reddish outside, having a narrow 

 (smooth and continuous callous rib within. Columella some- 

 what straightened, calloused, often very indistinctly excised 

 at the junction with the basal lip. Parietal callus thin, 

 translucent. 



Length 6.2, diam. 2.7, length aperture 2.5 mm., whorls 6 

 (Fig. 33, Middlesex). 



Length 6.8, diam. 2.6, length aperture 2.7 mm., whorls 5y 2 

 (Fig. 35, Gilbert White's estate, Selbourne). 



America : Point Barrow, Alaska, south in the Rocky Moun- 

 tains to the Mexican boundary; eastward south to Washing- 

 ton, D. C. and Missouri, with varieties in the Southern 



