II. ON A HETEROCERCAL FISH FOUND IN THE BLUE LIMESTONE SERIES OF THE LAVENTILLE HILLS.
II. ON A HETEROCERCAL FISH FOUND IN THE BLUE LIMESTONE SERIES OF THE LAVENTILLE HILLS.
By R. J.Lechmere Guppy, F.L.S., F.G.S., etc. (Pl. VIII.)
Proceedings of the Scientific Association of Trinidad p 181 -182
In a paper on the Blue Limestone of the Laventille Hills (Proc. Scient. Assoc. Trin., 1877, p. 109), I referred
to the discovery of a fish in one of the beds of the series. I had not then seen the specimen, but it has since
come into my possession, and is now exhibited to the Association. It consists of part of the vertebral column with
the tail-fin of a heterocercal fish. There are about thirty vertebrae present, and the rays of the tail are about
fifteen in number. There are traces of fine needle-like spines extending backward from the vertebrae near the tail.
The length of the specmen is nearly six inches (15 centimetres) ; the anterior portion is nearly straight, the
posterior part slightly curved. The thickness of the stoutest vertebrae is 5 millimetres they are nearly all of
the same dimensions up to the origin of the caudal fin, whence they rapidly taper off to its extremity.
The specimen came from the Piccadilly quarry on the east side of Port of Spain. It is exposed on the surface of
a thin dark-red micaceous sandy lamina, the usual parting between the beds of limestone in the quarry named. There
is not a vestige of dermal tissue or any other portion of the fish, except those described above. (See Plate VIII.)
Notwithstanding the meagerness of the characters afforded by the specimen I venture to assign it a provisional
name, and a place among the Ganoid fishes, as Acanathodes elongatus. The genus Acanthoides, to which I refer
our fossil, is characteristic of Devonian and Carboniferous rocks ; and, supposing my determination to be near
the truth, the additional evidence thus furnished is in favour of the view taken by me in the paper referred to
at the commencement of this notice as to the probable age of the Blue Limestone series, and its entire distinctness
as a formation from the mica and talc schists and sandstones, the clayslate and crystalline limestones of the Caribbean
group.
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