56 BULIvETlN OF THE BUREAU OF FISHERIES. 



It is well to point out that the meshes of the net should be of such a size as to per- 

 mit the small shells to pass through and remain at the bottom. Some small mussels 

 will undoubtedly be held in the net by the mud and larger shells, but these can be culled 

 out readily an^ returned to the water without any material injury. 



It may be noted that occasionally some of the thinner-shelled mussels, such as the 

 floater, paper-shell, etc., are pierced by the teeth of the dip net, which, of course, kills 

 the mussel. These shells, however, are not now of any commercial value. 



SHOULDER RAKE. 



The shoulder rake can be used to advantage in comparatively swift water, espe- 

 cially when the bottom is not too hard and is free from hang-ups such as rocks and 

 sunken logs. The implement consists of a metal rake about i foot long and provided 

 with lo to 12 coarse teeth or curved tines, which may be about 9 inches long (PI. XXIX, 

 fig. 2). The rake is securely bolted to a wooden handle 15 to 20 feet long, its length 

 being adapted to the depth of water. A basket, made of poultry-wire netting, is 

 attached to the rake and handle in such a way as to afford a concave receptacle for 

 the shells. A small board, about 10 inches by 2 feet, is usually fastened to the handle 

 approximately i yard from the base. The method of operation is rather simple, 

 though laborious. The boat in which the work is carried on is anchored over the 

 mussel bed, and the rake is placed into the river at the head of the boat and slowly 

 worked down to the stem, when it is raised to the surface. The shells are thrown into 

 the boat. The board attached to the handle offers resistance to the current, and 

 thus is of considerable assistance in raising the rake, as well as in driving it dowTi- 

 stream over the bed; it therefore has the same function of an underwater sail as the 

 mule used in crowfooting, but the power of the current acts only upon the rake, 

 and not upon the boat. The shoulder rake may be made from a coke fork. The tines 

 are cut to the desired length, heated, and bent at right angles to the handle. A long 

 handle must, of course, be substituted for the short handle of the coke fork. 



The results of this method are generally satisfactory, if the shells are relatively 

 abundant. Small shells inadvertently taken can be thrown back mth assurance, 

 generally, that they will live. 



The shoulder rake is a common implement on the Mississippi River and other 

 streams. On the St. Francis River, Ark., it is the principal method employed in the 

 summer and fall, while the crowfoot is chiefly used in the high water of spring. The 

 fork, to be described later, is also used in very low water. 



SHELIv TONGS. 



The shell tongs, or scissor forks, are used to some extent on the upper Mississippi, 

 the Cumberland, the White, and some other rivers where the wcfirk can be carried on 

 satisfactorily in rather deep water. It is possible, of course, to work between the free 

 spaces of a series of logs or other obstructions. It is essentially a grapple, consisting 

 of two rakes, or forks, on the ends of long handles which are pivoted together about 2 

 feet from the lower end, after the fashion of a pair of scissors (Pi. XXIX, figs, i, 2, 

 and 3). The method of its operation is similar to that of the oyster tongs; the appli- 

 ance is lowered into the water from an anchored boat, then bv bearing down on the 



