relative to the Mytilus lithophagus. 273 
nonnunquam pollicem lata et ultra 3 longa, Maris Mediterranei fra- 
gilt, Indici coriacea, stris transversis arcuatis exarata, nigra, badia 
aut virescente, intus opalino-cerulescente, albido-argentea, aut mar- 
garitacea." Linneus does not mention these strig, and he 
quotes Rumpfius's figure, which does not express. them; but 
perhaps we may say it is scarcely worth quoting. I had not an 
immediate opportunity of examining his other quotations. Re-. 
specting the shells which I had, the honour of presenting to the 
Society, Dr. Maton, V.P.L.S. and the Rev. Mr. Rackett, F.L.S. _ 
have been so good as to give their opinion, in a very learned. . 
and ingenious paper, which appears to show that those are va- 
rieties of M. lithophagus. We do not mean to contradict such 
great authority ; but having the opportunity of comparing them 
"by our usual aid of drawings, we avail ourselves of a- vacant 
spill in £e Liners S Buont, adii the whole: to th ae 
"Three o or v years since, 1found sibobgr some stones (perhaps 
ballast) at the Wapping-docks, a fragment of a calcareous rock. 
` I detached a piece, to examine the nature of the perforations, 
and found that the Mytilus lithophagus (the striated one here 
figured) filled some of them. "These stones appeared to have 
lain some time out of their proper element ; for the animals had 
apparently been dissolved. by putrefaction so long since, that no 
smell remained. "Phe shells were mostly mutilated: however, 
. upon diligent search, I found. one or two sufficient to examine as 
| to the species, and found them to agree with the description of 
Gmelin as above, and with his reference to the figure of our ac- 
-curate countryman Lister. In the spring of 1804, some stones 
— (seemingly ballast stones) were laid in Tothill-fields, Where, $ 2 
© found those which I presented to the- Linnean Society. "These, 
besides a striking ae pecting!y owe MA ide. T 
= vor. vir aru - Aud fig uti tec! 
