588 BRITISH PAL/ZOZOIC FOSSILS. [ Pisces, 
third the depth of the body; head very obtusely rounded, nearly semicircular, depressed, twice as wide as long, 
the length being only two-thirds the depth of the body; seales thick, nearly equilateral except on the flanks, 
where they are one-third higher than long, length of each about one line, surface minutely and uniformly 
punctured under the lens, the pores rather distant ; two anal fins very small, ovate, their own length apart, 
the second touching the caudal; one large triangular dorsal fin, longer than high, opposite the space between 
the two anal fins (anterior dorsal not seen). 
Easily distinguished from the other species of Osteolepis by its very wide, short figure. From the great 
width of the head it is almost always found with the anterior part of the body crushed vertically. The 
teeth are very small, close and slender. 
Position and Locality—I have seen five specimens from the Old Red nodules and schists of Caithness 
and Orkney. 
Explanation of Figures.—Plate 2. D. fig. 4, natural size; fig. 4a, scales of ditto, magnified two and half 
diameters; the two lower scales shewing the external polished and punctured surface with their articular margins ; 
the two upper being impressions of the inner surface, to shew the narrow longitudinal sulcus corresponding 
to the articular ridges on the under side of the scale. 
OSTEOLEPIS MACROLEPIDOTUS (Val. and Pent.) 
Ref.—Ag. Poiss. Foss. t. 2 4, fig. 1. (not 2). 
Dese.—About six inches long and one inch deep; body nearly of equal depth throughout, the pedicle of 
the tail being more than half the greatest depth of the body; head obtusely subtrigonal, about one-fifth the 
length of the body : scales about a line long, those of the body twice as high as long, those of the tail equilateral ; 
puncturing of the surface very fine, close, uniform: first dorsal about a third less than the second, and its 
own height in advance of it; second anal touching the caudal fin, which is very obliquely concayo-truncate. 
Position and Locality.—Not uncommon in the Old Red sandstone of Orkney. 
OSTEOLEPIS MAJOR (Ag.) 
Ref—Ag. Old Red. t. 19. fig. 1 to 3. 
Desc.—Very slender, of nearly equal depth from head to tail; length about nine inches, depth one inch 
four lines; head small, obtusely pointed, little more than one-sixth the entire length ; scales of the body about 
three lines long, and about two high, punctures of their surface few, large, irregularly scattered, and three or 
four times their diameter apart; tail small, short, slightly forked; dorsal and anal fins small, their height and 
length about equal. 
Position and Locality.—Not uncommon in the Old Red sandstone of Lethen Bar. 
OSTEOLEPIS MICROLEPIDOTUS (Val. and Pent.) 
Ref.—Ag. Poiss. Foss. t. 2c, fig. 1 to 4. 
Desc.—Length about five inches; fusiform, deepest in the middle, tapering slightly to the head, and 
rapidly to the tail, the depth being one-fifth of the length; tail shorter and less obliquely truncate than in the 
O. macrolepidotus ; scales about one line long and about one-third higher; surface under the lens very minutely 
and uniformly punctured. 
Deeper, shorter, and more rapidly tapering than the O. macrolepidotus, but having scales pretty nearly 
similar both in size, shape, and puncturing ; the fins slightly more remote from each other than in that species. 
Position and Locality —Not uncommon in the Old Red sandstone flags of Orkney. 
