Olicancilleria Braziliensis d'Orbigny. 4. Olicancilleria auricularia, d'Orbigny. 5. Olivina puelchana, d'Orbigny. 6. Buccinanops cochlidium, d'Orbigny. 7. Buccinanops globulosum, d'Orbigny. 8. Colombella sertulariarum, d'Orbigny. 9. Trochus Patagonicus, and var. of ditto, d'Orbigny. 10. Paludestrina Australis, d'Orbigny. 11. Fissurella Patagonica, d'Orbigny. 12. Crepidula muricata, Lam. 13.

Of marine animals there remain to be noticed a small Octopus, a Loligo, two Chiton, Patella, Crepidula, Pilcopsis, Fissurella, Calyptræa; of Concholepas, only empty shells; a large Mytilus, a small Modiola, Turritella, Turbo, Balanus; and a Holothuria of the variety Psolus.

I did not observe here any distinct proofs of recent elevation; but in a bed of very soft sandstone, forming a fringe-like plain, about sixty feet in height, round the hills of mica-slate, there are shells of Mytilus, Crepidula, Solen, Novaculina, and Cytheraea, too imperfect to be specifically recognised.

Kent, the assistant-surgeon, was so kind as to make for me some measurements with the barometer: he found many marine remains along the shores of the whole bay, at a height of about twenty feet; and from the hill of Sentinella behind Talcahuano, at the height of 160 feet, he collected numerous shells, packed together close beneath the surface in black earth, consisting of two species of Mytilus, two of Crepidula, one of Concholepas, of Fissurella, Venus, Mactra, Turbo, Monoceros, and the Balanus psittacus.

Sowerby, with the Pyrula, the Venus meridionalis, the Crepidula gregaria, and the Turritella ambulacrum, and T. Patagonica. The evidence taken altogether indicates that this great tertiary formation is of considerable antiquity; but when treating of the Chilean beds, I shall have to refer again to this subject.

All these shells now live on this coast, and most of them in this same bay. I was also struck with the fact, that the proportional numbers of the different kinds appeared to be the same with those now cast up on the beach: in both cases specimens of Voluta, Crepidula, Venus, and Trochus are the most abundant.

Cardita Patagonica, G.B. Sowerby. 7. Mactra rugata, G.B. Sowerby. 8. Mactra Darwinii, G.B. Sowerby. 9. Trigonocelia insolita, G.B. Sowerby. 11. Crepidula gregaria, G.B. Sowerby. 13. Voluta alta, G.B. Sowerby. 14. Trochus collaris, G.B. Sowerby. 15. Imperfect fragments of the genera Byssoarca, Artemis, and Fusus.