accompanied
them, he immediately, from their zoological characters alone,
pronounced them to belong to the chalk series. It is well known that
this learned naturalist divides all fishes into four great classes,
from the nature of their scales; two of these, the Ctenoid and Cycloid, never
make their appearance in any of the rocks beneath the chalk, and it was
from his knowledge of this fact that he decided my specimens to be from
that formation, as they consisted chiefly of individuals of the Ctenoid and Ct/cloid groups.
The fishes are in a most perfect state of preservation, and, as I have
already stated, are included in an impure fawn-coloured limestone; the
blocks, however, in which they are preserved, are only nodules
contained in the yellowish coloured sandstone. They have in general
somewhat the form of the imbedded fish, and the carbonaceous matter was
apparently aggregated round them by chemical attraction from the
sandstone while in a soft state; these nodules being harder than the
sandstone, have, by its gradual decay, accumulated at various places
along the acclivity of the range, and I possess specimens both from the
east and west side of it.*
On
the evening of the 23rd of December I had an invitation from Lieut.
Col. Joao Jose de Gouvea, a gentleman to whom I brought letters, to
accompany him and the Visitador to a place called Macape five leagues
to the east of the Villa da Barra do Jardim, whither they were going to
pass Christmas Day. This I gladly accepted, having been already
informed that a large deposit of fossil fishes existed there. We
started at eight o'clock on the morning of the 24th, and as the
Visitador was not to return, he was accompanied for nearly a league
from the Villa, by about half a dozen of the most respectable persons
in the neighbourhood, Senhor Gouvea, his lady, and Senhor Machado, and
I went on to Macape. At about half a league from the Villa we cnte red
*
The fishes were found by M. Agassiz to be all new species, and he has
described them in the Edinburgh New Philosophical Journal for January,
1841. I also possess, from the same rocks, specimens of two species of
very minute bivalve shells, a single valve of a Venus, and casts of a univalve shell, all apparently new.
