214 COLLECTING SHELLS. 



We have still to describe the manner in which this instru- 

 ment is used for the fishing of shells. A cord is passed 

 through the ring attached to the point of the dredge, another 

 cord is attached to the middle of the rod, 6 c, by a knot which 

 embraces the rod, b c, the perpendicular branch A D, and 

 the small cross-bar I>y at the point where they unite. When 

 the boat has reached the place of fishing, the dredge is thrown 

 out at the stern in the manner in which an anchor is thrown 

 out. The last-named cord serves to keep the dredge in its 

 place, the plate being turned below till it arrive at the bot- 

 tom of the sea, and to prevent it from being overturned by 

 the way. When the dredge has reached the bottom, it is 

 hauled along by rowing and sailing. Should the dredge be 

 stopped by any rock or irregularity at the bottom, the rope 

 attached to the ring should be pulled. When the bag is sup- 

 posed to be full, the dredge is drawn on board by the cap- 

 stan, and the bag is emptied of its contents. 



Different species of sea-weed are frequently covered by 

 minute shells. Weeds should always be carefully examined. 

 Many of the smaller and microscopic shells are found at high 

 water-mark among the fine dross and drifted fragments of 

 shells : this sand should be brought home and examined at 

 leisure. To facilitate the process, a small wire-cloth sieve 

 should be made of about six or seven inches square, and all 

 the sand sifted through it ; and the shells left. See Plate 

 v., fig. 7. 



OF THE DREDGING-BAG. 



This is the most simple apparatus for fishing shells. It is 

 a large net in the shape of a bag. The mouth of this bag is 

 kept open while at the bottom of the sea, by means of a 

 stick placed transversely, keeping the margins apart from 

 one side to the other. This stick is equal to the diameter 

 of the aperture of the bag, and as it is placed horizontally, it 

 divides that aperture into two halves, the one inferior, and 

 the other superior. The whole circumference of the lower 

 part is furnished with small pieces of lead, whose weight 



