176 



SHELLS AND SHELL-FISH. PART I. 



dentally explains the essential characters of Cochlicopa. 

 Quoy and Gaimard have figured the animal of the last 

 sub-genus, and M. Ferussac of this, which is distin-. 

 guished by the very backward position of the shell ; but 

 the typical form of Cochlicopa appears to be oblong 

 ovate, the spire and aperture nearly equal, the whole 

 shell distinctly striated longitudinally, and the outer lip 

 forming a sinuated curve near its base ; the substance is 

 almost always very thin ; and the colour is light fawn, 

 never marbled or banded transversely, but sometimes 

 longitudinally : those species which pass into Macro- 

 spira have such a long spire, that, but for the oval 

 aperture and regular strife, they would not be known. 

 The species appear confined to the tropical latitudes of 

 the Old and the New World. On the remaining sub- 

 genera, viz. Macrosjnra Guild., Leucostoma, and Acha- 

 tinella, nothing more can here be said. 



(16.5.) The next genus, Bulimus, is a most exten- 

 sive and varied one. It represents the typical Helices, 

 or snails ; and has, consequently, the aperture perfectly 

 entire, the end of the pillar being blended with the 

 outer lip : except in one of the sub-genera. Auricula, 

 the pillar has neither teeth, folds, nor plaits ; and even 

 in this solitary group, the largeness of the body-whorl, 

 the shortness of the spire, and the thickened margin of 

 the outer lip, are all certain indications of its belonging 

 to the genus Bulimus. The Bulimi, in fact, possess 

 all the characters of the genuine Auriculcp, but without 

 their folds. There is no perceptible difference in the 

 animals of the two typical sub-genera ; and that of two 

 of the others are unknown. 



(166.) We shall connnence the survey of this ex- 

 tensive group at that point where it joins Achatina. 

 This union is effected by our new sub-genus Lepto- 

 spira, which, as its name implies, has the spire exces- 

 sively long and slender ; their form, in fact, is precisely 

 like that of the Macrospira, but the aperture is entire, 

 and the outer lip thickened. A remarkable shell in our 

 cabinet, once the property of the duchess of Portland, 



