NATURAL HISTORY SOCIETY OF GLASGOW. 195 



Arriving now at the fourth part, viz., How to collect, I will 

 first refer to the metliod of procuring the aquatic kinds 

 generally. 



In order to obtain the greatest number of these in the shortest 

 possible time, it is necessary that one should be provided with 

 a wire sieve, to which can be joined a common walking- 

 stick when required. Then, when collecting, with the stick 

 joined to the sieve, you reach the latter as close to the roots 

 of the plants as possible, and sweep it along quickly for a yard or 

 two, keeping it well down, when any shells hanging by the plants 

 are either jerked or swept into the sieve. In cases where the water 

 is very deep it is not necessary that the sieve should be kept more 

 than twelve or eighteen inches down. 



Another way is by uprooting the plants and then examining 

 them closely. The Pisidiums, Planorhis nitickis, Cyclas cornea, and 

 lacustris, are found principally at the roots, the others on the 

 stems. Several species are also found on stones and mud; Ancijlus 

 fluviatilis is always on the former in shallow and broken 

 currents of clear water while Linmcea peregra is found in stagnant 

 water on both. 



In collecting land shells the following requisites should be 

 carried— viz., a botanical lens for viewing the smaller specimens, 

 a glass cap box for holding them, and a small wide-mouthed 

 bottle for containing the larger sorts. Stones and pieces of 

 decaying wood should be turned over and carefully, examined, 

 also the parts of old walls uncovered by moss, young nettles also, 

 as these seem favourite food with many of the Helices. But the 

 most economical and productive method of obtaining the minute 

 shells is by taking home a quantity of leaves, say in a large 

 vasculum, and after drying them on a tray, carefully searching 

 the debris which will be found beneath. By this plan you 

 concentrate any specimens present, while at the same time you 

 are, as it were, coUectmg at home, and can begin and leave off 

 as it suits your convenience. 



It is recommended in Jeffrey's work to examine moss 

 for shells, but so far as I have observed very few are to be 

 found in moss. I have taken home several times great quantities 

 of it from various localities and different situations, and seldom 

 found more than a specimen or two of Zonites oMarius, or Helix 

 rotundata. It is otherwise with damp leaves, as if there be shells 



