82 
ing Bulla sopita, Brand. Fossil. Hanton. Fig. 29, a. and Bulla volu- 
tata, Brand. Fossil. Hanton. Fig. 75, another, and apparently a more 
appropriate place has been allotted them, in a former part of this 
volume (Letter VI. p. 54 ;) and with respect to Bulla simulata, 
Brand. Fossil. Hanton. Fig. 61, it certainly can have no claim to be 
considered as a Bulla, the spire being acutely pointed, the cauda 
produced, and the columella plicated. 
The bullites of the environs of Paris appear to be divisible into four 
species : B. ovulata, B. striatella, B. cylindrica, B. coronata. 
XLVII. Bulimus. An ovate or oblong subturreted shell : the 
opening entire, oblong, and longitudinal, having, in adults, an ex- 
ternal reflected margin : the columella smooth, the base entire, not 
spread out. 
The oblong and longitudinal opening of the shell is, according to 
Bruguiere, the chief characteristic of this genus : Lamarck, also, 
adopts this distinguishing mark ; and, by the. assistance of other es- 
sential characters, has formed from the genus Bulima, of Bruguiere, 
not only this genus, but those of Agathina, Lymnea, Melania, Au- 
ricula, and Pupa. 
The shells of this genus are inhabited by an animal much resem- 
bling that which belongs to the genus Helix. The shells of the two 
genera, however, differ, in the opening of the Helix being wider than 
it is long, whilst that of Bulimus is always longer than it is wide. 
The snail, too, has a round or orbicular shell, and that of the Bulimus 
is oblong, conical, or turriculated. The margins, in Bulimus, are 
separated in the upper part ; but in Helix, the last turn but one of 
the spire projects into, and thereby contracts, the opening. The 
shells of Bulimus are distinguished from those of Melania, by their 
having no widening at the base of their opening ; and from those of 
Lymnea by their not having a distinct and very oblique fold, which 
is seen in the shells of the last-mentioned genus. Bulimus is a land 
shell ; but Lymnea and Melanea are fresh -water shells. 
