Jaw and Lingual Dentition of Pulmonata. 172 
Lingual membrane long and narrow. Teeth about 16-1-16. Centrals 
as usual in the Helicine (pl. xviii, fig. C). The side cusps and cutting 
points are well developed, the base of attachment longer than wide. 
Laterals of same type, but unsymmetrical, and consequently only bicus- 
pid. The change from laterals to marginals (8th and 9th teeth of figure) 
is very gradual, there being no splitting of the inner cutting points, at 
least not as in most species (see pl. xii, fig. E). Marginals (16th tooth of 
figure) very low, wide, with one inner, long, blunt cutting point, and one 
outer, small, blunt. 
The low, wide marginal teeth of this species are peculiar. 
Helix rufescens, Pennant (Fruticicola). 
Extracted from a dry English shell furnished by Mr. A. 
G. Wetherby. I include it here because the species has 
been introduced at Quebec. I was not able to illustrate it 
when treating of the Lingual Dentition of North American 
Land Shells, in Proc. Ac. Nat. Se. Phila., 1875, 214. 
There are 26-1-26 teeth. The characters of all are shown in my fig- 
ures. It will be seen that the transition from laterals to marginals (16 to 
19), see also Lehmann, in Malak. Blatt. xvi, is gradual. The inner cut- 
ting point is not bifid. 
Helix pubescens, Pfr. (Pruticicola). 
Etat, Ibe, We, 12, Baddhms Go Woe, I, lene. 
Jaw (pl. xv, fig. C) thin, semitransparent, low, slightly arcuate, 
ends scarcely attenuated, blunt; upper margin with a strong muscular 
attachment: no median projection to cutting edge; anterior surface with 
about 20 ribs denticulating either margin; these ribs appear in most cases 
to be broad, flat, with narrow interstices, but in others there are appear- 
ances such as I have described in Bulimulus limneoides (see below). 
Lingual membrane long and narrow (pl. xv, fig. D). Teeth as usual 
in the Helicine. The change from laterals to marginals is very gradual, 
not formed by the splitting of the inner cutting point. The 12th tooth 
(figured) shows the commencement of the transition. The 22d (figured) 
is a marginal tooth. The inner cutting point of the marginals is rarely 
bifid. 
Teeth about 24-1 -24. 
Helix Studeriana, Fér. (Stylodon). 
Seychelles, Consul Pike to Mr. T. Bland. 
Jaw stout, strongly arched, ends but little attenuated, blunt; anterior 
surface without ribs; there are, however, afew, coarse, broad, vertical 
