On the Fossils, from the High Andes, collected by David Forbes, Esq., F.R.S., F.G.S.

The number of species that we recognize in this collection, made with so much perseverance and at great personal hazard, are— 5 Lower? Silurian (Bilobite-schists). 14 Upper Silurian (grey sandy schists and sandstones). 3 Devonian. 13 Carboniferous. D'Orbigny's collection of Silurian fossils contained 10 species, of which none have occurred to Mr. Forbes. They are— Cruziana rugosa. Cruziana furcifera. Orthis Humboldtii. Lingula marginata. Lingula Muensterii. Lingula dubia. Graptolites dentatus. Phacops (Calymene) Verneuilii Phacops (C.) macrophthalma? Asaphus Boliviensis. There is some doubt about both his species of Phacops. They are probably Devonian. Adding these to our list, we obtain 27 or 29 Silurian species for the Central Andes, belonging to a fauna specifically different from that of any other quarter of the world. I venture without hesitation to assert that the identifications by D'Orbigny with European forms, where I am acquainted with the species, are wrong. I am obliged to say this much, since that distinguished author has fearlessly united things which differ by the most obvious external characters, and has lent the sanction of his great reputation, on such evidence as this, to a former community of species, and an equable diffusion of heat. In regard to the Carboniferous forms, where M. D'Orbigny is unwilling to allow more than, a close analogy between the two continents, I am again compelled to differ from him, but it is in an opposite direction.