The list of fossils described in this paper and their stratigraphical distribution is shown in the Table on p. 122.

The Kainella and Leiostegium zones of the Quebrada del Toro are the equivalent of the Late Ozarkian of Western North America.

The fauna of the arenaceous-calcareous beds of the marine-glacial deposits of the Saladillo group is not characteristic enough to enable an exact determination of the age. Nevertheless, from the stratigraphical position of these beds, they could be considered as indicating Upper Beekmantown age.

The lower part of the Parcha group, with the single determinable fossil Basilicoides taurinus gen. et sp. nov. has been provisionally referred to the Llandeilian.

The faunule of the Asaphellus zone of the Quebrada de Chalala shows affinities with part of the Tremadocian of England, the Tomkolian of South Chosen, and the upper zones of the “ Ceratopygeregion ” of Scandinavia.

The stratigraphical relationship between the Kainella and Leiostegium zones of the pre-Puna and the Asaphellus zone of Purmamarca is not known.

On the eastern side of Barnavave, at the immediate junction of the igneous mass with the surrounding limestone and about a quarter of a mile south of the fault which crosses the mountain, there is an isolated outcrop of a fine-grained, speckled rock which clearly invades the limestone at this point. The rock includes xenoliths broken from the limestone and also others of igneous origin.-and smaller dimensions. Microscopical examination proves the rock to be a syenite of unusual character which carries a small amount of quartz. It is possibly the rock referred to by Harker.

The effect of waves on a shore depends largely on the angle of approach, for the energy of the advancing waves tends to erode the headlands and drift the products of erosion into the bays. Wave refraction applies to waves approaching the shore in any direction, but is only ideally developed in ordinary weather conditions or by approaching waves caused by distant storms. Locally developed storm waves usually approach the shore at an oblique angle to its general trend, owing to the failure of wave refraction and are the most effective where locally they meet the shore at right angles. Beach drifting will be in operation along the section of the shore which happens to be at an angle oblique to the direction of the approaching waves.