31 
labrum reflected, with a slightly projecting dentiform callus near 
the base on the inner edge ; labium with an oblique tooth on the 
middle ; umbilicus rather large, profound, exhibiting all the 
volutions. 
Breadth rather more than sev,en-tenths of an inch. This shell 
inhabits the State of New York. It is closely allied to H. 'pro- 
funda JSfoh.^ but may be distinguished by its smaller size and 
armed labium. Its aperture also is much more dilated than that 
of \hQ profunda^ PI. 15, f. 4. 
H. PERSPECTivA, Nob. — Is common in the North-west Terri- 
tory ; it varies in being smaller, and in the circumstance of the 
labrum embracing a somewhat smaller portion of the penultimate 
volution. 
H. ARBORA, Nob. — Common in this territory. 
H. CHERSiNA, Nob. — A variety of this species is not uncommon 
in the North-west Territory. It differs in the greater rotundity 
of the upper part of each whorl, and in the somewhat less rounded 
or more flattened figure of the labrum. It may, however, prove 
to be a distinct species, when many specimens of chersina can be 
had to compare with it. 
H. Alternata, Nob. and H. albolabris. — On our return 
homewards, these two species were not found until we arrived in 
the secondary country towards the eastern extremity of Lake 
Superior. 
H. THYROiDus, Nob. — Falls of Niagara. 
H. LI GERA, Nob. — North-west Territory. 
ViTRiNA PELLuciDA of Authors. — This shell was first found 
near Coldwater Lake in latitude 48f north, under stones, fallen 
timber, &c. It afterwards frequently occurred in similar situa- 
tions, until we approached Lake Superior, when it was no more 
seen. Like its congeners, the inhabitant is much too large to 
retract within the shell, and a great portion of the body is there- 
fore constantly exposed. No species of this genus has been 
hitherto found in this country ; the discovery of this shell is 
therefore the more interesting. The specimens which we collected 
do not appear to differ in any respect from those of Europe. 
Bulimus lubricus of Authors. — The species occurred under 
stones, &c., on the shores and islands of Lake Winnepeck and 
Lake of the Woods. It is altogether similar to the European 
