BULLA. 89 



information as to the generic cliaracter ; the difference alleged 

 by Mr. Swaiason and Mr. Gray being a comparative thinness in 

 the outer lip. PL xiv. fig. 283. 



BULINUS. Brug. (Bulinus, Lam.) Fam. Colimacea, Lam. Li- 

 macinea, Bl. — Descr. Oval or oblong, Hght, covered with a thin 

 epidermis ; spire obtuse, variable in length and in the number of 

 whorls, which are generally few ; aperture wide, oval, rounded 

 anteriorly ; outer lip simple, usually reflected, joining the colu- 

 mella without a sinus ; inner lip reflected over part of the body- 

 whorl. The Bulini are land shells, found in many parts of the 

 world. — Obs. The genus Bulinus can only be distinguished from 

 Helix by its oval form ; it forms part of the genus Helix of De 

 rerrusac, under the sub-generic designation of Coehlostyla. It 

 is known from Achatina by the absence of the notch at the point 

 of union between the irmer and the outer lips. The young are 

 produced from eggs, which are as firm and opaque as those of 

 birds. (See Introduction.) Bulinus rosaceus, fig. 282. B. Guada- 

 loupensis, fig. 283. B. Lionetianus, fig. 284. B. lubricus, fig, 

 285. Many new species were brought to this country by Mr. 

 Cuming, and are represented in the Conchological Illustrations, 

 published by the Author at 50, Great Eussell Street, Bloomsbury, 

 (in parts 21, 22, 23, 26, 27, 30, 31, 34, 35, 137 to 146, 185, 186.) 

 Species occur in Europe, West Indies, Brazil, and South America 

 generally. Beeve's Monograph contains 662 species. Some small 

 species are British. PL xiv. fig. 282. 



BULLA. Auct. Fam. " Bulleens," Lam. Akera, BL — Descr. 

 Generally thin, smooth, oval, oblong or cylindrical, more or less 

 convolute ; spire short, depressed, or hidden by the last whorl ; 

 aperture long, wide in front, gradually narrowing towards the 

 spire ; outer lip thia ; inner lip spread over a part of the last 

 whorl. — Obs. The shells composiag this genus are very variable 

 in form. The light horny species with an elastic lip is called 

 Akera, fig. 247. The more decidedly convolute species with hidden 

 spires are the Atys, Montf. B. jSTaucum, fig. 250. B. Lignaria, 

 fig. 251, is Scaphander of Leach. The light, thin species, with 

 extremely wide aperture, fig. 248, is Bullsea aperta. Lam. The 



