NEW FRESH WATER AND LAND SHELLS. 17 
nearly allied to Amnicola orbiculata, herein described, but may be distinguished by its 
being a smaller shell, and being less round in the aperture. The base of the lip is disposed 
to be slightly angular: the aperture is about one-half the length of the shell. 
IO. (La.) 
The genus Io was proposed by me for Mr. Say’s Fusus fluviatilis. 1 subsequently 
added the spinosa, which may perhaps prove to be only a variety of the other. ‘The ¢ene- 
brosa now proposed, will make three species of this genus. 
To TENEBROSA. 
Testa fusiformi, subtenui, subnigrd, levi; spird conicd; suturis via impressis; anfractibus senis, subplanulatis; 
aperturd enormiter pyriformi, intus purpured. 
Shell fusiform, rather thin, nearly black, smooth; spire conical; sutures scarcely impressed; whorls six, flattened; 
aperture irregularly pear-shaped, within purple. 
Hab. Tennessee. §S. M. Edgar. My Cabinet, and Cabinets of Mr. Edgar and Prof, Troost. Diam. 
.48, Length .75 of an inch. 
Remarks.—A single specimen only was brought by Mr. Edgar from Tennessee. Itisa 
small specimen, and may be immature. Aftera good deal of hesitation, I have determined 
to give it a place among the species. It seems to me to be very distinct in colour. ‘The 
channel is more curved to the left and backward, than in Mr. Say’s species. It has no 
trace of spines or tubercles, and is dark all over. I do not know if it ever occurs banded. 
Read June 18, 1841. 
Hent1x Mopiniana. 
Testa subglobosd, rufo-corned, nitidd, perforata; spird brevi, obtusa; 
aperturd lunatd; labro reflexo. 
Shell subglobose, reddish horn colour, shining, perforate ; spire short, obtuse; sutures impressed; whorls six, convex ; 
aperture lunate; lip reflexed. 
Hab. Vicinity of Mobile, Alabama. Mr. Charles Lea. My Cabinet, and Cabinet of T. G, Lea. 
Diam. .30, Length .25 of an inch, 
Remarks.—My brother, T. G. Lea, sent me several of this species, with other Helices 
collected near Mobile. A single specimen only was perfect in the lip, the remainder 
being immature. It is not easily confounded with any other of our species. In form it 
is somewhat like H. jejuna, (Say,) but is not more than one-fourth the size, and differs in 
colour, ‘There is rather a deep groove behind the lip, which is reddish. The umbilicus is 
small. 
suturis impressis; anfractibus senis, convexis; 
HELIX MINUTISSIMA. 
Testa subglobosd, supra obtuso-conoided, subtus convexd, fusco-corned, minutissimé striata, 
suturis impressis; anfractibus quaternis, rotundis; aperturd subrotundd; labro acuto. 
umbilicatd; spird brevi; 
Shell subglobose, above obtusely conical, below convex; brown horn colour, very minutely striate, umbilicated; spire 
short: ee y : 
hort; sutures impressed; whorls four, round; aperture nearly round; lip acute. 
VOL. Ix.—8 
