I.—On a New Species of Dipterus

Abstract

From the Old Red Sandstone of Caithness, four species of Dipterus were originally named by Sedgwick and Murchison, those being as follows:— 1. Dipterus brachypygopterus, anal fin short. 2. D. macropygopterus, anal fin long. 3. D. Valenciennesii, small in size, narrow in shape. 4. D. macrolepidotus, not characterized although figured. It is evident from the figures of “D. macrolepidotus” that it does not belong to the same genus, even to the same family, as the other forms. Those have circular scales, whereas in “macrolepidotus,” the scales are rhombic, and the head bones are clearly seen to be very different from those of Dipterus.