Pecten Dufreynoyi, d’Orbigny, “Voyage” Part Pal. Turritella Andii, d’Orbigny, “Voyage” Part Pal.
Astarte Darwinii, E. Forbes. Gryphaea Darwinii, E. Forbes.
An intermediate form between G. gigantea and G. incurva.
Gryphaea nov. spec.?, E. Forbes. Perna Americana, E. Forbes. Avicula, nov. spec.
Considered by Mr. G.B. Sowerby as the A. echinata, by M. d’Orbigny as certainly a new and distinct species, having a Jurassic aspect. The specimen has been unfortunately lost.
Terebratula aenigma, d’Orbigny, (var. of do. E. Forbes.)
This is the same variety, with that from Guasco, considered by M. D’Orbigny to be a distinct species from his T. aenigma, and related to T. obsoleta.
Plagiostoma and Ammonites, fragments of.
The lower layers of the limestone contained thousands of the Gryphaea; and the upper ones as many of the Turritella, with the Gryphaea (nov. species) and Serpulae adhering to them; in all the layers, the Terebratula and fragments of the Pecten were included. It was evident, from the manner in which species were grouped together, that they had lived where now embedded. Before making any further remarks, I may state, that higher up this same valley we shall again meet with a similar association of shells; and in the great Despoblado Valley, which branches off near the town from that of Copiapo, the Pecten Dufreynoyi, some Gryphites (I believe G. Darwinii), and the TRUE Terebratula aenigma of d’Orbigny were found together in an equivalent formation, as will be hereafter seen. A specimen also, I may add, of the true T. aenigma, was given me from the neighbourhood of the famous silver mines of Chanuncillo, a little south of the valley of the Copiapo, and these mines, from their position, I have no doubt, lie within the great gypseous formation: the rocks close to one of the silver veins, judging from fragments shown me, resemble those singular metamorphosed deposits from the mining district of Arqueros near Coquimbo.
I will reiterate the evidence on the association of these several shells in the several localities.