PULMONATA. 137 
This genus was first separated by Adanson, and afterwards by Humphrey, for shells 
previously referred either to Volutaor Mitra. Subsequently Lamarck defined it more 
exactly under the present name, by which it isnow known. ‘The animal resembles that 
of Cyprea in all essential particulars, and like it, is furnished with lobes to the mantle, 
which can be extended over the shell so as to cover the spire, which thus acquires an 
enamel-like covering resembling that of the Cowries. The condition of the spire, th 
number and the arrangement of the columellar plaits, and the simple or crenated state 
of the outer lip, have been used as characters for the separation of the J/arginelle into 
various genera; but these divisions do not appear to be warranted by generic dis- 
tinctions in the animals and consequently, have not been generally adopted, but have 
been regarded as sections merely of the present genus. Mr. G. Sowerby (Gen. Shells), 
has suggested that the JJarginelle may be classed under two natural sections; the 
first comprising the species in which the spire is distinct, the columella furnished 
with four folds at the base, and the outer lip characterised by a thick fold-like 
border along the outer margin; the other consisting of the species in which the 
spire is short, almost concealed, the columellar plaits more numerous, the an- 
terior plaits being the larger, and the outer lip but slightly thickened. The first 
section corresponds with G/adella (Swain.) and Phenospira (Hinds); the latter represents 
Persicula (Schum.), Volutella, Gibberula, Marginella (Swain.), and Cryptospira (Hinds). 
The recent Marginelle are numerous; they chiefly inhabit the tropical and sub- 
tropical seas, where they are found in shallow waters; they appear to abound on the 
coasts of Africa, and some few small species, belonging to the second section, are found 
in the Mediterranean. In the fossil state they first appear during the tertiary epoch. 
In the French eocene beds, eleven species occur, of which seven have been described 
by Lamarck and Deshayes ; and of these, several are found in England, Germany, and 
Belgium. Six species from the corresponding formations in Alabama (U.S.), have also 
been described by Conrad and Lea: and in the more recent deposits in Europe and the 
United States, twenty additional species have been found. 
Section A. Spire apparent. 
No. 80. MARGINELLA EBURNEA. Lamarck. Tab. XVIII, figs. 1 a—e. 
MARGINELLA EBURNEA, Lamk. 1803. Ann. du Mus., vol. ii, p. 61, No. 1; and vol. vi, 
t. 44, fig. 9. 
— —_— Roissy. 1804. Buff. Moll., vol. vi, p. 9, No. 4. 
— — Lamk. 1822. Hist. nat., vol. vii, p. 359, No. 15. 
— _— Brogn. 1823. Sur les ter. tert., du Vicent., p. 64, No. 1. 
— — Defr. 1823. Dict. des sci, nat., vol. xxix, p. 145. 
ellis) 
