78
FISHES.
towards the Teleosteous type, the number of separable bones
Fig. 39.—Skull of Polypterus. (After Traquair.)
Fig. I. Upper aspect of the Primordial Cranium, with the membrane-bones removed. Fig. II. Lower aspect of the same. Fig. III. Side view, with the membrane-bones. Fig. IV. Lower aspect of the Skull, part of the bones being removed on one side. The parts shaded with oblique lines are cartilage of the primordial skull.
An, Angular; ao, anteorbital; Ar, articulary; B, basal; D, dentary; E,
