198 
previous season, and though they were not found in as lar^e 
numbers as the astyris , yet their presence inclined me to ques- 
tion the conclusions arrived at during the season of 1878. 
I accordingly collected a large number of the astyris and 
placed them in an aquarium jar with a number of young oys- 
ters, changing the water constantly and inspecting the ani- 
mals frequently. 
These observations were continued for over a week, and at 
the end of that time both oysters and astyris were alive, but 
there was no evidence of any boring, nor did any inspection 
show an inclination in that direction upon the part of the as- 
tyris / on the contrary, they soon left the shells and went to- 
the bottom of the jar. 
I then collected a number of urosalpinx cinereus and sub- 
jected them to the same test. 
At the end of four days one oyster had been bored and one 
welk was found at work on the shell of another. 
The rough welk is known to do great injury to the oyster- 
in Long Island Sound, and the destruction of the young 
alluded to in my previous report, as due to the drills, may be- 
effected by this animal. 
That large numbers are destroyed by the welks cannot be- 
doubted, but it is possible that the astyris may also assist in 
this destruction. 
A more extended investigation of this question than I was 
enabled to make is desirable. 
An analysis of several specimens of the water of the Sound 
and of the Bay, made by Prof. C. E. Monroe, of the ETaval 
Academy, is appended to this report, for use in comparing tile- 
localities investigated with others whose investigation may be- 
subsequently attempted. 
The specimens have been selected from those taken in dif- 
ferent stages of the tide and from different sections. 
The only noticeable change on the beds this season was that 
the amount of red sponge appeared to be much less than in 
1878. In other respects they are, to outward appearances, in 
a similar state, though the dredgers report them a& mu chi 
broken up, with an increased amount of debris. 
