BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [34] 



10 feet ill diameter, according to the size of the net, and stretched 

 with very little slack, so that when the hoop is held horizontally the 

 net will not fall below it more than a foot or two at most. This hoop 

 is attached by four cords, fastened to it and meeting over the center of 

 the net at a distance of 6 or 8 feet from the hoop, to a line of sufficient 

 length to reach the bottom, which is supplied with a small buoy at the 

 surface. In the center of the net a bait is tied, preferably of dead and 

 even iDartially decayed fish or flesh, since the carnivorous mollusks are 

 apt to be attracted by the odor of any decaying animal matter. The 

 net can be put down and left a convenient length of time and then 

 hauled up. This should be done very carefully, so that the net will 

 keep as nearly as possible in a horizontal position, and if any mollusks 

 have crawled upon it to get at the bait they will be found in the slack 

 of the net when it reaches the surface. If the net is hauled up incau- 

 tiously, so as to turn it over or tip it sidewise to an inconvenient angle, 

 of course the collector is likely to lose whatever may be upon it. In 

 the writer's experience the most productive time for the use of such 

 nets is at night, and it will be often found advisable to put the net 

 down in the evening and raise it early in the following morning, when 

 the results will be usually found more satisfactory than if the net has 

 been merely allowed to remain on the bottom during the hours of day- 

 light. In northern waters the collector is sometimes disappointed by 

 the voracity of isopod Crustacea, which appear in such swarms as to 

 devour the bait in short order. 



STEAM DKEDGING. 



If the collector lives near one of the larger cities, where small tug- 

 boats can be had for moderate hire and good dredging grounds are not 

 too far off, it will be found profitable to obtain the use of a tug on some 

 convenient occasion, since dredging by steam is far more effective, more 

 rapid, and more easy than by any other method. The handling of the 

 dredge is practically the same whatever power be used to drag it, but 

 the use of a tugboat reduces the inconveniences to a minimum and 

 enables the collector to go over more ground in the same time than can 

 be covered by any other method. A search for suitable dredging 

 grounds will require some experience and time. Usually grounds 

 found available for ordinary line-fishing, if the water is not too deep, 

 will be profitable for dredging, unless the bottom be very rocky and 

 irregular. Inquiry of fishermen and watermen will often save a col- 

 lector time and trouble, for such men are familiar with the grounds 

 over which they are accustomed to fish and can designate the particu- 

 lar kind of bottom from long experience. 



OUTFIT. 



Besides the coarse sieve already mentioned the collector may, if he 

 likes, provide himself with a finer sieve for sifting fine sand and mud 



