Pvn H,i I'UitlS

AVICULA. 97
vessels are bound. Miss Hutchings, who (according to
the late Mr. James Sowerby) discovered this species in
Bantry Bay, was infinitely better acquainted with seaweeds
than with shells. I have some of the latter which
Mr. Dillwyn received from that lady, as collected by her
in Bantry Bay, and which are unquestionably Mediter-
ranean and not Irish. One of them is Area barbata.
Such mistakes often happen in spite of the best inten-
tions. I do not say, however, that A. hirundo has never
been found in Ireland, or that it may not hereafter be
rediscovered there. It occurs, but very rarely, in the
Coralline Crag. Its exotic distribution is wide, and
comprises both sides of the Mediterranean, as well as
the Adriatic and iEgean Seas, the Canary Isles, Madeira,
and the Azores. Mr. M 'Andrew has taken it on the
shore near Gibraltar, and in the Canaries as deep as 50
fathoms.
The shell has a very remarkable shape, not unlike
that of a swallow on the wing. Two of Lamarck's
species of Avicula (Atlantica and Tarentind) appear to
be the same as the present species, representing the
younger and mature states of growth. The former he
describes as having the valves unequal in size, and the
latter as being equal- valved. If one of these specific
names had to be selected, the description of "Atlan-
tica " would therefore be more appropriate than that of
" Tarentina M to our shell. Linne's diagnosis of Mytilus
hirundo is equally applicable ; and it would be a pity to
reject that time-honoured name in favour of any other
given by subsequent
when he described, in his f
writers. Turton was mistaken
Conchological Dictionary/ a
second species {A. morio) as British, on the authority of
Dr. Leach. The latter distinctly stated that species to
be exotic; but in his account of the genus Avicida
F