72 
PROCEEDINGS OE THE PERTHSHIRE SOCIETY OF NATURAE SCIENCE. 
The above note may be applied to other plants than the 
dog violets. Members should keep in mind that it re¬ 
quires no botanical skill to collect and preserve common 
plants, and that any Perthshire specimens will always be 
useful and valuable for our herbarium. 
The following paper was read:— 
' Notes on the Mollusca of Perthshire. ” By Mr Henry 
Coates. 
Twelve years ago a small volume was published con¬ 
taining the proceedings of our Society for the Session 
1869-1870. In that volume will be found no less than five 
communications devoted to the mollusca of Perthshire, 
some recording the occurrence of certain species, others de¬ 
tailing the distribution of groups. During the years that 
have intervened since then I think I am correct in saying 
that the total number of papers that have been brought 
before us on this subject does not exceed the number above 
mentioned. This is to be regretted, as there is much in¬ 
teresting work to be done both in studying the structure 
and habits of these creatures, and in working out their 
distribution in our district. 
Some may ask in surprise, what interest is to be found 
in the contemplation of snails and slugs, beyond the 
facts that some have s. ells and some have not, and 
that all have the unpleasant propensities of destroy¬ 
ing our favourite plants, and of crawling across our 
path after every summer shower of rain ? In reply I would 
ask you to remember that in our own county alone there 
are to be found some five dozen different species of these 
despised creatures, each having its own peculiarities of 
structure, its own habits and haunts. The only parapher¬ 
nalia necessary for the study of the mollusca are a supply 
of pill-boxes and a good pocket-lens ; and, for aquatic 
species, a drag net. The microscope and dissecting in¬ 
struments are valuable adjuncts if we have time and in¬ 
clination for a more thorough investigation. 
The all-important question with the beginner is— 
Where are the objects of our search to be met with ? 
To this the simplest reply is, in any spot which has 
been for long undisturbed by the hand of man. They 
are to be met with in every glen, either adhering 
to the damp rocks and stones, buried amongst the 
moss and loose debris, or crawling up the blades of 
the reeds and grasses. They are to be found in every 
disused quarry, in the stone heaps gathered off the 
fields long ago, and on the sunny banks of old pasture 
edging streams and rivers. Every pond and ditch which 
has stood for fifty years or more will yield a rich harvest 
of aquatic species, and even our swiftest rivers are the 
home of the hardy pearl mussel. But we must remember 
that not a tenth of these shy creatures will reveal them¬ 
selves to the casual observer, and this for two reasons. In 
the first place, they generally lie concealed in crevices of 
the rocks, or beneath stones and moss, where the rays of 
the sun cannot penetrate to dry up the mucus in which 
their bodies are enveloped, and from these retreats they 
only crawl abroad after a shower of rain has moistened 
the ground. In the second place, our difficulty is not 
only to unearth them, but to see them when unearthed, 
for some are not more than the twentieth part of an inch 
in diameter, and the fortieth of an inch in height, and 
many are of the same dusky hue as the earth itself. Our 
search may be prosecuted nearly all the year round, but I 
have generally found autumn to be the best collecting 
season, as the ground is then warm and moist, and the 
mollusca besides are then in best condition. In the 
cold weather of spring and in the dryest days of 
summer they retire farther into their retreats, though 
it is interesting to note that even in the depth of 
winter a few have the hardihood to venture out of 
their hiding-places, and have been seen crawling on 
the snow itself. 
Of the mollusca comprised in the following list, most 
have been taken by my brother and myself. Speci¬ 
mens of these, or more correctly of their shells, will 
be found in the collection which we have formed for the 
Museum of the Society, and the notes regarding them are 
the result of jottings made during our excursions to pond, 
stream, wood, and glen. In order, however, to make the 
catalogue more complete, reference is made to some other 
species which have already been recorded from the district, 
but with which we have not yet met. In all such cases 
the recorders’ names are mentioned. The “slugs,” or 
mollusca having an internal instead of an external shell, 
have been excluded from the list, as I have not yet been 
able sufficiently to work up their distribution. These, 
however, may appropriately form the subject of a separate 
paper, and I commend the study of them to members of 
the Society as a field in which much has yet to be done. 
1. Sphcerium corneum. The only representative of this 
genus yet found in the district occurs in tolerable abund¬ 
ance in most of our old ponds. It may be distinguished 
from its allies the Pisidia by the dark horn colour of 
the shell. 
2. Pisidium fontinale seems to be about equally dis¬ 
tributed throughout the ponds of the district with the 
other two species. 
3. P. pusillvm, and 4. P. nitidum. These minute 
