Obliged for letter about cirripedes attached to turtles' backs. Genus is Chelonobia, Leach. Cirripedes do not penetrate skin, but surrounding tissue grows up around them.
Asks RB to send S. American Balanus. Already has specimens from Irish coast.
Down Farnboro' Kent
My dear Sir
I am very much obliged to you for your kindness in writing to me on the several curious points, specified in your letter, touching the Cirripedia.
I think I certainly know the large species, attached to turtles' backs
& sometimes penetrating even their bones; it is the Chelonobia of Leach
& Astrolepas of Gray. I have not yet
particularly attended to this genus. I have dissected with
care Coronula & Tubicinella & the only conclusion which I was able to
arrive at was, that the cirripedes did not in fact penetrate the skin, but that the
surrounding parts of the skin of the cetacea grow upwards, the part immediately under
the cirripede not growing or even being absorbed by the action of the downward pressure
of the cirripede which grows at its base.—
I always have felt some doubt regarding this, & especially in regard to
Chelonobia.— It is quite new to me that this
genus should make burrows or move at all laterally, if I understand you
rightly: but I do not think a cast w
I have a vast number of specimens in the Turtle-shell, & these hereafter I will closely inspect: Lithotrya, Alcippe of Hancock & a nov. genus, have an undoubted power of mechanical burrowing, but this is different from anything which Chelonobia could possess.—
If you w
Very many thanks for your offers of sending me notes of the occurrence of species of
Anatifa on the Irish Coasts; but having had M
With my sincere thanks. Believe me | My dear Sir | Yours sincerely | C. Darwin
- f1 1429.f1The year is established from the mourning border of the stationery used by CD after the death of Anne Darwin.
- f2 1429.f2Living Cirripedia (1854): 382.
- f3 1429.f3Darwin did not begin working on this genus of Balanidae until 1852 (‘Journal’; Correspondence vol. 5, Appendix I).
- f4 1429.f4CD described this attachment of Chelonobia in Living Cirripedia (1854): 390–2.
- f5 1429.f5See letter to Robert Ball, 8 June .
- f6 1429.f6See letter to Robert Ball, 8 June .
- f7 1429.f7A reference to Cryptophialus. The three genera are mentioned in Living Cirripedia (1854): 512 as the only three to which CD attributed mechanical powers of excavation. He based his opinion on his examination, especially in Lithotrya, of the serrated structure of the lowest scales of the peduncle (see Living Cirripedia (1851): 337).
- f8 1429.f8See Correspondence vol. 4, letter to William Thompson, [1 March 1849].