151 
AMPU LLAEI A. La March. 
Gen. Char. Shell univalve, ventricose, sub glo- 
bose, with a projecting’ spire; base umbiii- 
cated ; aperture oblong, entire, with no thick- 
ening on the left lip. 
In the shells of this genus the last whorl is, as La 
Marck observes, at least four times as large as the 
preceding, which gives the ventricose form to the whole. 
The recent species are inhabitants of rivers in warm 
climates, and are covered with a polished, generally 
greenish, epidermis, no vestige of which is to be traced 
in the otherways well preserved fossil species. La Marck 
and his followers are inclined to establish a distinct 
genus for these fossils, because they were probably 
marine shells, as they accompany other marine genera : 
the want of an epidermis might serve as one of the cha- 
racters ; the lower part of the mouth being somewhat 
reflected (vers ant) would form another. 
AMPULLAR1A acuta* 
TAB. CCLXXXI Y.— Three Upper Figures. 
Spec. Char. Ventricose, smooth, with a small 
acute spire ; umbilicus half closed, small ; 
aperture ovate, elongated. 
Sin. Amp. acuta. La March Env. de Paris, 147. 
Helix mutabiiis. Brander,jigs. 58 and 59. 
This shell is much longer than wide, although the spire 
does not exceed one-fourth of the length : the umbilicus 
is most generally only half covered by the left lip of the 
mouth, but La Marck observes it is sometimes quite 
covered : the mouth is twice as long as wide, acute at 
the upper angle, and slightly curved on the body of the 
shell : below it is rounded with a depressed, nearly re- 
flected edge : the left lip is entire. 
Sent me from near Christchurch by my ©Id friend the 
Rev, Mr. Iremonger long since, and lately by Miss 
Beminster, 
