VOLUTA. TRACHELIPODA. 29 
Calpurna Leathesi. Plate IV. fig. 9. 
The Calpurne inhabit the ocean ; one species occurs in the British seas, and 
the C. Leathesi is found fossil in the Crag at Walton. 
This genus was instituted 'by Montfort for the reception of Ovula Leathesi, 
whose characters do not agree with those of the genus Ovula. 
TRIBE II.— COLUMELLARIA. 
Shell destitute of a canal at the base of the aperture, but 
provided with-a more or less distinct subdorsal notch, and 
folds upon the columella. 
Genus VII.L—VOLVARIA. — Lamarck. 
Generic Character.—Shell cylindrical, convolute ; spire 
nearly hidden, and depressed, terminating in a small blunt, 
hardly salient apex; aperture narrow, extending the whole 
length of the shell, somewhat wider and truncated at the 
base ; columella with three or four oblique folds near its 
base ; outer lip denticulated. 
Volvaria acutiscula, Plate IV. fig. 22. 
The shells of this genus are known only in a fossil condition, and found in 
the Calcaire grossier of Paris, Bordeaux, Grignon, and the London Clay at 
Hordwell. 
Distinguished from the Bulle by the plaits on the base of the columella, 
and by t’xcir transversely striated exterior. 
Genus VIII.— MARGINELLA. — Lamarck. 
Generic Character.— Shell oblong-ovate, smooth ; spire 
short, in some species nearly hidden ; aperture elongate, 
narrow, wider below than above, and slightly notched at 
the base; outer lip retlected, provided with a longitudinal 
varix or thickening; lower portion of the columella furnished 
with several folds or plice. 
Marginella quadruplicata. Plate IU. fig. 20. 
Section 1.— Spire short, distinct ; base of the columella 
with six plaits, the lower one largest. Marginella glabella 
is a type of the section. 
Section 2.— Spire short, hardly visible, with some plice 
at the base of the columeila. Type Marginella Persicula. 
The Marginelle are marine shells. The only fossil species known, is the 
M. quadruplicata, plate III. fig. 20, and belongs to the latter section. 
Genus 1X. —VOLUTA. — Linneus. 
Generic Character. — Shell subovate, surface generally 
variegated with different colours and markings, for the 
