266 Mollusca of Middlebury, Vt. and Vicinity. — 
Arr, IV.—Catalogue of the Mollusca of Middlebury, Vt., and 
vicinity, with observations ; by C. B. Apams, Prof. Chem. and 
Nat. Hist. Middlebury College, Memb. Bost. Soc. Nat. Hist. 
Tue utility of catalogues of species, which inhabit distant 
parts of this country, as materials for ascertaining their geograph- 
ical distribution, need not be urged. Even a single local cata- 
logue cannot but be of interest and utility. It is obviously im- 
portant that the stations and the abundance or scarcity of the 
several species should be designated. Such catalogues should 
also be drawn up by those whose residence in the region enables 
them to make numerous observations at all seasons, to detect the 
rare species and those which appear only for a very limited time 
during the year. 
In obtaining materials for the following catalogue, my acknowl- 
edgments are due to aor George W. Benedict, of Burlington ; 
also to Messrs. K. Prescott, Luther H. Sheldon, and M. W. John- 
son, who have been my assistants in the department of Natural 
History, and who have detected some of the rare species, which 
might otherwise have escaped search. That other species may 
yet be found is by no means improbable, for a species, whose 
habitat should be as circumscribed as that of Vitrina pellucida, 
Drap., (see following remarks,) appears to be in this vicinity, may 
elude the researches of many years. But after the careful search, 
which has been made in various places and in every station, ¢S 
pecially by my assistants, it cannot be expected that any important 
additions will be made. 
Me anta. 
M. depygis, Say. It is remarkable that no species of the fam- 
ily Melaniana occur in the New England States, with this single 
exception, although some are abundant in New York. This spe 
cies occurs here only in Lake Champlain, where it was first found 
by my friend Prof. George W. Benedict, in Burlington. It is 
very rare. I have found several imperfect specimens, and but 
one with the animal, at Shoreham. 
PaLupIna. 
P. decisa, Say. This species, so common in the streams and 
ponds of New England, occurs plentifully in Otter Creek, but 
