296 CRETACEOUS GASTROPODA 
[ Naticodon, Ryckholt, 1847, (?) (Mél. Pal. pt. I, 1852, p. 75), has been proposed 
for a number of species similar to Ampullina, but provided with a tooth on 
the inner lip. The genus, as restricted, may better be placed in the Vayzxorip2, 
though there have also been species described under the name of Naticodon, which 
do not appear to possess a columellar tooth, and in such cases they hardly can 
be distinguished from <Ampullina. Deshayes, confirming Raulin’s suppositions 
(Anim. s. vert. foss. de Paris, 2nd edit., Vol. ITT, p. 88), retains also Deshayesia in the 
family Narrcrp#; I shall, however, subsequently state my reasons for classifying 
the same in the family Nzzirmz]. 
There are further a number of cretaceous species, like Nat. carinata, Rom. (Nordd. Kreidegeb. 
1841, p. 83, (Nat. unicarinata, Geinitz, Char., 1842, p. 74), Nat. Valdensis, Pict. and Camp. 
(Mat. Pal. Suisse, 3me. Ser., pl. 74, fig. 4), and others, which have a raised ridge placed in or about 
the middle of the last volution. It is very probable that this ridge terminates on the outer lip 
with a narrow emargination or notch, somewhat similar to that known in Neritoma, Morris, 
(Neririp2); but as none of the above mentioned species have been found in a well preserved state, 
it is impossible to form a correct idea of their relations to that fossil genus. 
5. Ampullinopsis, Conrad, (Smithson. Miscel. Coll., No. 200, Check list invert. 
eocene foss., 1866, p. 20,) with the species dm. Mississipensis, Con.; we are as yet 
only in possession of the name. 
6. Huspira, Agassiz, 1837, (Sowerby, Min. Conch., Germ. edit., p. 14, and 
p- 820). Lunatia, Lamarck? apud H. and A. Adams, Gen. I, p. 206 ; idem Gray, 1847, 
Proceed. Zool. Soe., Lond., p. 149. The species referred to this genus are distin- 
guished by a regularly conical spire, resembling that of Amaura and Amauropsis, 
a moderately callous inner lip and a slightly excavated columella; the last volution 
is inflated in proportion to the previous whorls. The recent forms are mostly uni- 
coloured and especially numerous in the eastern seas, though not so common as 
species belonging to several other genera of the Naricrpm, (Natica and Mamma). 
H. and A. Adams (Gen. I, p. 207,) accept the genus in the same sense, as 
pointed out by Agassiz, under the name of Lwnatia, for which they quote Lamarck’s 
authority. We have not been able to procure Lamarck’s reference, but Gray used 
the name first in 1847. Swainson proposed in 1840 for the species of Huspira the 
name Globularia. Neither of these names of Gray and Swainson can have priority 
before that of Agassiz. H. and A. Adams quote the name Huspira as a synonym 
of Ampullina, which is not correct. 
The same authors (1. cit., p. 207,) proposed for Nat. flava, Gould, from Mas- 
sachusetts Bay, the sub-generic name JAecrybia ; but as the shell of this species is 
thin, and the columella almost solid, it would probably be better to transfer it to 
Amauropsis, with which also the plain and uniform colouring agrees. 
A very large number of fossil species, usually described under the name of 
Natica, belong to the genus Huspira; and some of the older (especially triassic) 
forms often resemble species of Macrocheilus and Stilifer, though they always have 
a thicker shell. 
The cretaceous species of Huspira are not yet discriminated, though tolerably numerous. In 
addition to the species noted as Zwnatia in Meek’s Check. list of jur, and cretaceous foss., North Am., 
