; FOOD OF THE OYSTER, CLAM, AND RIBBED MUSSEL. 381 
for the usual rope of the net to be firmly wound around it in order to 
(‘keep the latter in position. This arrangement allows the use of both 
met and dredge separately or together with very little trouble or 
jexpense. When the apparatus is in use, the dredge is drawn along 
‘on the bottom in the direction of the arrow, while the net is held about 
.a foot above the bottom and a few feet in front of the dredge, so that 
ithe mud stirred up by the latter does not interfere with the net, and in 
\the latter only those objects are taken which are normally suspended 
in the water passing over the mud bank. 
In order to study the diatoms over as wide an area as possible, 
collections were made daily from Newport News down to Hampton, 
,and even from points several miles outin the bay. [rom these catches 
about 50 species of diatoms were drawn on the spot. For staining the 
diatoms, the lower algw, and other low forms of life, I employed the 
method described farther on, which I think offers some advantages 
worthy of consideration. Several jars full of diatoms were preserved 
and carried to Baltimore for classification. I have not, however, been 
able to find a reliable work on the classification of American diatoms, 
and as specialists assure me that such a one does not exist, this plan 
had to be abandoned, since the time at my disposal just now does not 
permit me to undertake it. Nevertheless, such a classification would be 
of great value, and if the necessary collection of diatoms from different 
points of the American coast could be obtained to enable such a work 
to be done on a broad basis, it would also pay from a practical stand. 
point. It would be of great interest to so determine the habitat of the 
different species as to ascertain which grow on the bottom and which 
are freely suspended inthe water. At the same time a careful study 
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