THE NAUTILUS. aL 
HELIX HORTENSIS: I am sending under separate cover a spec- 
imen of Helix hortensis Miller. It was found in a prehistoric 
shell-heap on Mahone Bay, about 75 miles west of Halifax, 
N. S.—W. J. WourTEMBERG. 
A SynonymicaL Norte: The shell described and named by 
Pilsbry and Bryan in Tue Navrtitus, XXXI, 3, 1918, p. 99, 
pl. TX, as Drupa walkere from Honolulu Harbor, is the same 
species which was described by G. B. Sowerby in the Annals 
and Magazine of Natural History, Ser. 8, Vol. XVI, p. 166, 
pl. X, 1915, as Pentadactylus fusco-imbricatus. A recent letter 
from Sowerby and Fulton suggested this after an examination 
of a specimen sent to them. A careful comparison of the de- 
scriptions and figures convince us of the same conclusion. All 
the specimens known are from the Honolulu Harbor dredgings 
from May to August, 1915. The teeth vary from 5 to 7 in the 
specimens before us. We hope to make a study of the varia- 
tions of this and other shells later. 
F. GRINNELL, JR., 
J. M. OsTERGAARD. 
INSECT LARV# DESTROYING Puysa.—There is a small artificial 
pond in Waveland Park which joined my former home grounds 
in Des Moines, Iowa, that I had never considered of much im- 
portance conchologically, owing to its small size and rather 
recent construction. A visit to it one day in the summer of 
1907, however, only added greater strength to Mr. Simpson’s 
motto, ‘‘ Look everywhere.’’ 
I found here a form of Physa integra Haldeman quite plenty, 
but nearly all dead. They were enveloped in what at first ap- 
peared to me to be a growth of moss, but which Dr. C. M. 
Child of the Department of Zoology, University of Chicago, 
pronounces as insect cases, ‘‘ probably some dipterous insect, 
but none of the men in the Department are able to ideal 
more exactly the insect that is responsible for them.’’ As I 
have heard nothing further, it is fair to presume that the insect 
is new or little known. 
The deposition and multiplication of these microscopical in- 
