Mollusca. 
MOLLUSCA. 
Cypree, Olive, and the greater number of what is termed 
Sa —~~ porcellaneous shells. In general, however, it happens that, 
Formation 
of a collec- 
tion of 
shells. 
when shells become dry, they lose much of their natural 
lustre. This may be very easily restored, by washing them 
with a little water, in which a small portion of gum arabic 
has been dissolved, or with the white of an egg. This is 
the simplest of those processes which are employed, and is 
used not only by the mere collector, but by the scientific 
conchologist. There are many shells of a very plain ap- 
pearance on the outside, by reason of a dull epidermis or 
skin with which they are covered. This is removed by soak- 
ing the shell in warm water, and then rubbing it off with a 
brush. When the epidermis is thick, it is necessary to mix 
with the water a small portion of nitric acid, which, by dis- 
solving a part of the shell, destroys the cohesion of the epi- 
dermis. This last agent must be employed with great cau- 
tion, as it removes the lustre from all the parts exposed to 
its influence. The new surface must be polished with lea- 
ther, assisted by tripoli. But, in many cases, even these 
methods are ineffectual, and the file and the pumice-stone 
must be resorted to, in order to rub off the coarse external 
layers, that the concealed beauties may be disclosed. Much 
address and experience are necessary in the successful em- 
ployment of this last process. But it must be confessed that 
the reward is often great. When thus prepared, even the 
common mussel is most beautiful. 
The arrangement of shells in a cabinet must depend, in a 
great degree, on the taste and fortune of the collector. If 
ornament is the object in view, it will be indispensably ne- 
cessary to have the shells placed in glass cases, where they 
may be distinctly seen. But where a collection of shells is 
formed for amusement, they may be kept in drawers, each 
species placed in a paper case, or in a cup of wood, glass, or 
porcelain, with a label attached, intimating its name, and 
the place from whence it was obtained. In this manner, 
both univalves and bivalves may be conveniently disposed. 
But as many of the former are very small in size, it is often 
necessary to fix them on pieces of card, that they may be 
preserved, and rendered easier of inspection. When neigh- 
bouring species are thus brought together, they can be easily 
examined with a lens. 
About the end of the sixteenth century, many individuals 
began to form collections of testaceous bodies. The first 
museum of this kind, of any consequence, was begun by 
Benedict Ceruto, and afterwards augmented by Calceolari. 
An account of the specimens contained in it was published 
by Olivi, in 1585, and, in 1622, Chiocco published plates of 
the shells. After this period, in proportion as collections of 
testaceous bodies became numerous, various works on shells 
made their appearance. These were not published for any 
scientific object, but merely to teach collectors the names 
of the different specimens in their museums. As works of 
this sort, we may mention the Historia Naturalis of John- 
ston; the Gazophylacium Nature of Petiver; the Amboin- 
she Rariteithamer of Rumphius ; and the Wondertoonel der 
Nature of Vincent. To this list we might add many mo- 
dern works, which are termed Systems of Conchology. 
From the labours of this class of conchologists the science 
has derived many important advantages. A taste for the 
study has been widely extended; the shells of distant coun- 
tries and shores have been brought together; and numerous 
engravings of these bodies have been published. In this 
manner the labours of the man of science have been greatly 
facilitated, and our knowledge of nature enlarged. 
The formation of a collection of shells is absolutely ne- 
cessary to the successful prosecution of the science of con- 
chology. To accomplish this, much care and attention are 
requisite. Shells must be sought for in their natural situa- 
tions, and obtained, if possible, with the animal alive. After 
the animal has remained dead in the shell for any length of 
time, it loses its lustre and transparency, and becomes less 
375 
valuable, either as an object of beauty or curiosity. Hence Mollusca. 
the collector must explore the sea-coast, the land, and the ~~ 
fresh water, in search of the testaceous animals which they 
support, for the purpose of obtaining ina perfect state their 
calcareous coverings. 
The sea contains more species of shells than either the 
land or the fresh waters, and presents to the conchologist an 
extensive field for observation. Many species of marine 
shells frequent the sea-shore, adhere to rocks, stones, or sea 
weed, or lodge in the clay or sand. These are termed L7#- 
toral shells, and are seldom found in deep water. The lit- 
toral shells are easily collected at ebb tide. Those which 
burrow in the mud or sand may be detected by a small de- 
pression which they leave on the surface as they retire below 
it. Other shells live in deeper water. To collect these the 
dredge must be employed; and if the shells be put into sea 
water after they are brought up, the animals may afterwards 
be examined with ease. Such collectors as have not the 
advantage of a dredge, should examine the refuse of fishing 
boats, and traverse the sea shore, and search the rejecta- 
menta, especially after a storm of wind. The roots of the 
larger fuc?, especially F. digitatus, which grows sometimes 
in four or five fathoms water, frequently contain a treasure 
of the rarer shells. 
During the ebb of stream tides, the conchologist ought 
to be very diligent. The rocks are then uncovered, and 
under the projecting ledges of the strata he will find many 
species of shells in very perfect state. 
In rocky shores it will prove a useful employment to turn 
over the stones which are scattered in the pools, near low 
water, and on the under side of these he will find a rich har- 
vest of Chitons and Cingule. 
In the tutts of Corallina officinalis, a number of the small- 
er shells are found concealed, likewise among the smaller 
Fuci and Conferva. When these bodies are brought from 
the shore, and put into a glass of sea water, the smaller shells 
will soon be perceived by their motions. 
When vessels which have been long at sea come into dock 
to be cleaned, their bottoms are often covered with shells, 
and with sea-weed, containing numerous rare vermes. To 
such situations the conchologist should resort ; and in these 
he will often be successful in finding the objects of his pur- 
suit. In illustration of this remark, we may mention the 
circumstance of the vessel employed at the Bell Rock as a 
floating light, having had her bottom covered with mussels 
three inches and a half in length, and upwards of one inch 
in breadth, although she had only been afloat three years 
and seven months. She was moored the 11th July 1807, 
and removed the 1]th February 1811. Previous to being 
moored, she was completely caulked and pitched. The sand 
on the shore likewise yields many of the smaller species of 
shells, and should be carefully examined with the micro- 
scope. 
When sea shells are obtained, they should be plunged into 
boiling water, to facilitate the extraction of the animal, and 
afterwards soaked in it for some time to remove the salt. 
They should then be cleaned with a brush, and all extran- 
eous matter removed. When the shells are not soaked in 
fresh water, the salt remaining soon attracts moisture, which 
speedily destroys the ligaments and epidermis. 
The land shells are more within the reach of the scientific 
collector. To obtain these, he has only to examine the cre- 
vices of rocks, the trunks of trees, decayed wood, moss, and 
brushwood. In summer, after a shower, the land shells are 
most easily procured. The animals come forth to feed on 
the moistened blade, and at that time, from their motion, 
may be very readily perceived. 
The land shells are very easily preserved. Almost all that 
is required is the extraction of the animal. 
The fresh water shells, though less difficult to procure than 
the sea shells, require more trouble than the land shells. A 
