io LAND AND FRESH-WATER SHELLS. 



abode. The rules are what I term "golden rules;" /.*., rules 

 not to be forgotten ; but the one rule of the assiduous collector is 

 to search in every crink and cranny, and never to pass over a 

 spot without a full examination of its whole surface. The imple- 

 ments needed for this collecting are few in number and inexpen- 

 sive. Two of them are given you by nature nimble fingers and 

 quick eyes ; one forms a companion in your walks, the walking- 

 stick ; the others, which will have to be purchased, are a dredge, 

 a scoop or a water-net, and a few chip boxes. The walking stick 

 will be useful for pulling water-weeds to the bankside, so that 

 they may be easily examined with the fingers for specimens. The 

 dredge will be needed for the collection of Unios, Anodons> 

 Sphcsria, and Pisidia, which, being bivalves, live almost entirely 

 on the bed of the pond or stream. This can be made after the 

 following figure of a net-dredge recommended in Messrs. Gray 



Fig. 2. -A Water-dredge (Woodward). 



and Woodward's companion volume, " Seaweeds, Shells, and 

 Fossils ; " but my preference is to having a properly weighted 

 square frame rather than a circular one, as it takes a larger area 

 of the water-bed at the same time, and, consequently, is more apt 

 to work up a larger number of specimens. The scoop is now 

 in general use, and is an exceedingly good implement to use 

 for sweeping among water-weeds which cannot be brought to 

 the bankside with the stick, and perhaps is more welcome 

 and more serviceable than the ordinary water-net, for which it 

 forms a substitute. Mr. Wallis Kew and I have taken a large 

 number of specimens with it from the Tottenham Marshes, 

 by the way, a happy hunting ground for the London collector. 

 Mr. Denison Roebuck has his made of copper, but zinc will be 

 found cheaper and nearly as serviceable a material. A circular 

 ring of zinc is made, of about an inch and a quarter in depth, 

 and of about eight inches in diameter. A perforated zinc bottom 



