54 BULLETIN OF THE BUREAU OF FISHERIES. 
smiths make them according to orders and with the material at hand. However, the 
various designs and patterns are very similar, the main differences being the size of the 
hoop and the length of the attached net. The method of operation is the same for all 
of them. 
The frame of the dip net consists of a heavy iron hoop of one piece flattened on 
one side. The general form, therefore, is somewhat triangular, the bottom being 
straight, while the two sides are curved and attached by bolts to a pole or handle 16 to 
20 feet long (fig. 4 in text and Pl. XXIX, fig. 4). A large net of 2-inch mesh, made of 
small chain or trot-line and having a capacity of a bushel or more, is fastened to the 
hoop by means of chain links, and trails behind it. A short bridle attached to the two 
Fic. 4.—The dip net used in taking fresh-water mussels. 
curved sides of the hoop lead forward to a single rope secured to the bow of the boat. 
To withstand the strain from dragging through the water and also to support the net 
with a heavy load of shells, the hoop is usually made of stout wagon-tire iron, about 2 
inches wide by 0.25 inch thick. The straight bottom is from 18 to 36 inches in length; 
the edge is bent downward and usually provided with coarse teeth 6 to 8 inches long, 
and at times two or three additional teeth are riveted to the curved sides, near the 
bottom. However,in some hoops the teeth are omitted altogether, since none are needed 
where the bottom of the river is composed of very soft mud. ‘The net varies in length 
