INTRODUCTION. 3 
For the better identification of species let me advocate the advan- 
iage of comparison e7 #zasse. When we compare two individuals we 
are as likely as not to perceive casual or individual peculiarities, 
whereas, if we have before us a series of (say) Myalinia cellaria 
and also a series of . g/abra, the eye catches the specific agreements 
and differences and rejects the individual ones. 
Doubtless every describer of shells has been puzzled to find simple 
geometrical terms suitable to their forms, which are often complex. I 
have followed the authorities in using such terms as ovate, szb- 
cylindrical, etc., though they are vague, and do not express to what de- 
gree the object is oval or cylindrical. Dr. Jeffreys calls Lzinnea stagnalis 
“* elongated,” which it certainly is; but what shafe is ‘‘ elongated ” ? 
This difficulty, however, affects the describer more than the collector, 
who can glance at a plate where the shell is figured. Some ludicrous 
results of attempting to realize form from description may be seen in 
the drawings of the old naturalist Gesner, who depicts elephants, 
whales, besides other beings more fearful and wonderful still, from 
the descriptions of persons who had seen them, or professed to have 
done so. 
THE PLEASURES OF COLLECTING. 
The pleasures of collecting anything are too patent to need to be 
dwelt on here, but the pleasures of collecting objects of Natural History 
in any branch have additional charms—the charms of the country. 
WAYS AND MEANS OF COLLECTING. 
I have often been asked by would-be collectors such questions as 
“* How do you set about collecting?” ‘‘ What implements are neces- 
sary?” and most frequently, perhaps, ‘‘ Where do you look for shells ? 
I know the ‘Garden Snail’ and one with yellow bands, but I never 
see all these you have in your cabinet.” 
To those desirous of information the following hints may prove 
serviceable :— 
