226 
Valtata akenipeea, Trans. Amer. Philos. Soc. vol. 4, N. S. In the 
Wissihickon and other streams of water in the vicinity of Philadelphia 
is the larvae of a common insect belonging to the Linnsean genus Phry- 
ganea, which constructs a spiral follicle precisely similar to the descrip- 
tion and figure above referred to, excepting, of course, that it is destitute 
of operculum, which the author says, in two of his specimens was 
‘ ‘ sufficiently perfect to exhibit a striated horny structure. ’ ’ The oper- 
culum seems to have been imperfect in both specimens, and we fear that 
a mistake may have been made, and that the V. arenifera, is in reality 
only the follicle of a larva and not the production of a molluscous ani- 
mal. It would be easy to make the necessary comparison, as the 
follicle is well known to most of the conchologists of that city. 
Caeacolla helicoides, ibid, is a variety a of Helix palliatay S., H. 
denotata^ Per. 
Helix caeolinensis, ibid, corresponds by description and figures with 
H. appressa, S., var. a. 
Melania tubeeculata, ibid, is a variety of M. stygia, S. 
Melania elongata, ibid, seems very closely related to M. elevata^ S., 
and may probably prove to be the same. 
[Amer.|Conch.[^p. vii.]* * 
Donax variabilis^ noh. Journ. Acad, Nat, JSci., vol 2, 
p, 305. FI 61,/. 1. 
Donax fossor, noh, Journ. Acad, Nat, Sci., vol, 2, _p. 306. 
FI 61, / 2. 
Cyrena CAROLINENSIS, ^osc. Fay. — NichohoF s Encyclopedia^ 
(3<^ American edition^ article Gonchology. 
Obs. It inhabits Mobile Bay, in the vicinity of Mobile, Ala- 
bama, and occurs fossil in the Newer Pliocene of North Carolina, 
near Newbern. — ED.f PL 62. 
Venus ALVEATA. — Fesc. Shell ventricose ; valves very thick, 
subtriangular, cordate, with eight remarkably thick, very promi- 
nent, much recurved, transverse approximate ribs, of an uniform 
thickness throughout, terminating abruptly at their anterior slope 
which is much impressed ; lunule cordate, included by an im- 
pressed line. 
* [No date is given for this part. It was printed after Mr. Say’s death, 
which occurred in Sept., 1833.— -En.] 
t [T. A. Conrad.] 
