half of the eye orbits were hollowed formed a pair of sweeping wings, and thus in the centre of the buckler we are presented with the figure of an angel, robed and winged, and of which the large sculptured leaf forms the body, traced in a style in no degree more rude than we might expect to see exemplified on the lichen-encrusted shield of some ancient tombstone of that House of Avenel which bore as its arms the effigies of the Spectre Lady. Children have a peculiar knack in detecting such resemblances; and the discovery of the angel in the cranium of the _Asterolepis_ I owe to one of mine. [Illustration: Fig. 29. PLATE OF CRANIAL BUCKLER OF ASTEROLEPIS.] It is on this inner side of the cranial buckler, where there are no such pseudo-joinings indicated as on the external surface, that the homologies of the plates of which it is composed can be best traced. It might be well, however, ere setting one’s self to the work of comparison, to examine the skulls of a few of the osseous fishes of our coast, and to mark how very considerably they differ from one another in their lines of suture and their general form. The cerebral divisions of the conger-eel, for instance, are very unlike those of the haddock or whiting; and the sutures in the head of the gurnard are dissimilarly arranged from those in the head of the perch. And after tracing the general type in the more anomalous forms, and finding, with Cuvier, that in even these the “skull consists of the same bones, though much subdivided, as the skulls of the other vertebrata,” we will be the better qualified for grappling with the not greater anomalies which occur in the cranial buckler of the _Asterolepis_. The occipital plate, _A_, _a_, _a_, (fig. 29,) occupies its ordinary place opposite the centre of the nape; the two parietals, B, B, rest beside it in their usual ichthyic position of displacement; the superior frontal we find existing, as in the young of many animals, in two pieces, C, C; the nasal plate I, placed immediately in advance of it, is flanked, as in the cod, by the anterior frontals, D, D; the posterior frontals, F, F, which, when viewed as in the print, from beneath, seem of considerable size, and describe laterally and posteriorly about one half the eye orbits, have their area on the exterior surface greatly reduced by the overriding squamose sutures of the plates to which they join; and lastly, two of these overlying plates, E, E,—which, occurring in the line of the lateral bar or beam, are of great strength and thickness, and lie for two thirds of their length along the parietals, and for the remaining third along the superior frontals,—represent the mastoid bones. Such, so far as I have been yet able to read the cranial buckler of the _Asterolepis_, seem to be the homologies of its component plates. [Illustration: Fig. 30. PORTION OF UNDER JAW OF ASTEROLEPIS, (OUTER SIDE.) (One half nat. size.)] [Illustration: Fig. 31. PORTION OF UNDER JAW OF ASTEROLEPIS, (INNER SIDE.)