Retrospective. Criticism. 451 
collection two beautiful specimens from the Indian Seas: both contain the 
perfect “ animal’’ within, and distinctly perceptible through the envelope. I 
selected them froma great many: all the rest were empty cases: the threads 
proceeding from the angles form beautiful curled. tassels. — J. Murray. 
Carmarthen, April 2. 1830. 
Buccinum lapillus.—Sir, Your correspondent G.J.,on Molluscous Animals 
(p. 44.), says that the Baccinum lapillus, is “ exposed for sale in large quan- 
tities in the fish-shops of the metropolis.’ He is certainly mistaken in the 
species: the only species of the whelk tribe sold in London, as an article 
of food, are the B. undatum, and the Murex antiquus Lin. It may lead 
young beginners into an error. The least observation will show how dif- 
ferent the species are; the B. lapillus not being one fifth the size of the 
other two. I am no draughtsman, or I would send you a sketch of the 
three. — A Constant Reader. Stepney, Jan. 28. 1830. 
Conway Pearl Fishery. — Two very different kinds of pearl are collected 
about the Conway: one kind, the produce of a fresh-water muscle, Mya 
margaritifera, called by the Welsh, Cregin y dylw (shells of the flood), or 
perhaps Cregin y deuliw (shells of two colours); from which very valuable 
pearls are sometimes obtained, not much inferior to the Oriental ones. I have 
seen a very beautiful pearl from a lake in Scotland half an inch in diameter, 
and of a perfectly hemispherical shape. They are taken in the upper part 
of the Conway, near Llanrwst, but the search is very precarious. The 
other kind is abundantly obtained from the common edible muscle, J/Z/tilus 
edulis, in the mouth of the river Conway, and in the Menai near Bangor. 
When the tide is out, numbers of people may be seen, of all ages, gathering 
the shells from the rocks and stones to which they are attached. The 
pearls yielded by these shells, though numerous, are small, irregularly 
formed, and of a bad colour, It is these pearls that are sent to London, 
and the destination of which is so mysterious. — W. Wilson. Warrington, 
June, 1830. 
Pearls in the Conway. (p.130.)—I suppose the misshapen so-called 
pearls sent to you must have been obtained, not from the J/ya margaritifera 
(U*nio elongata of Lamarck), but from the common muscle (Mytilus edulis) 
in which minute and misshapen and ill-coloured concretions are often 
found. My late brother found a very fine pearl in the common muscle: 
it was ofa perfect form and considerable size, that of an ordinary pea : it was 
unfortunately however of a purplish tint, and wanted all the rich brilliancy 
which so distinguishes the Oriental pearls. Though pearls are found in the 
shells of various Testacea, as the common oyster, J/ftilus edulis, Pinna, 
Haliotis, &c., I believe the Mytilus margaritifera and Mya margaritifera 
are those alone which yield the best supply as to colour, number, quality, 
size, and form, That rara avis the “ pink pearl” is found in one of the 
conchs. I have seen small Oriental pearls of a perfect form, yet in great 
variety of colours, in Earl Mountnorris’s collection ; and even when obtained 
from the “ pearl oyster” (muscle) as it is commonly called, the forms are 
sometimes fantastic enough. I have a very fine one, large; a complete 
biceps, resembling a double-headed shot; it is Oriental, and of the finest 
brillianey, but useless as an article for jewellery. The pearl fisheries of the 
Conway, and especially of Scotland, were once considerable, and charters 
were granted for their monopoly. I have been informed that a lady on 
the Conway nets nearly a thousand a year by the pearls of that river, 
ander a charter: doubtless these must be obtained from the AZya margari- 
tifera (the pearl muscle does not exist in the Conway), if this is actually 
the case, for it is probable I may have been misinformed. Poor persons 
pick out useless pearls, such as do not deserve the name of that beautiful 
concretion, the ornament of coronets and crowns, and vend them for a 
trifle. It is, however, some years now since I was on the Conway, and 
the delightful science of conchology formed then no part of my studies. 
