Fourth Order of the Hypersthene-Augite Andesites.
Characters.—Groundmass presenting a rudely granular
appearance or blurred mosaic (microfelsitic).
Formula.—Hypersth.-aug., matr., fels.
Remarks.—My sliced specimens (five) are too few for the elaboration of this order to which the classification employed for the other orders is scarcely applicable. This is due to the partial decomposition or imperfect development of the pyroxene of the groundmass. The general characters of the order are given on p. [291].