GLYPTOL.EMUS KINNAIRDI 465 
meets its fellow in the middle line, just behind the posterior edges of 
the principal jugular bones ; but their inner margins immediately 
diverge, passing backwards and outwards, and being continued in the 
same direction as far as the posterior edge of the operculum, by the 
inner edge of the posterior pectoral plates. The adjacent margins of 
the two plates seem to be firmly united together, and their outer sur- 
faces exhibit a marked sculpture, whose ridges are more evenly con- 
tinuous than those of the cranial bones. Two large triangular scales 
which fit in between the supraoccipital and the epiotic appear to 
represent some of the upper elements of the pectoral arch. 
The pectoral fins are not perfectly displayed in any specimen, but 
fig. 2, Plate II. [Plate 34], shows that they were well developed, being 
about as long as the head, and that they were provided with numerous 
long and delicate fin rays which beset the edges and extremity of a 
stout central stem, covered with rhomboidal scales. 
The ventral fins, smaller than the pectorals, were also, as figs. 2, 3, 
Plate I. [Plate 33], show, distinctly lobate, their central stem being 
covered with rhomboidal scales and terminating in a point, at about 
the middle of the length of the fin. 
The median fins present very distinct jointed fin-rays, and, as may 
be seen in fig. 1, Plate I. [Plate 33], the scales of the body are con- 
tinued on to the bases of the dorsals and anal, so as to give them, though 
to a far less degree, the lobate aspect of the pectorals and ventrals. 
Both dorsals are pointed at their extremities, and somewhat fan- 
shaped, from being narrower at their bases than in their posterior 
moieties. The first dorsal is smaller than the second. The anal fin, 
opposite the second dorsal, is about as jarge as the latter, and has the 
same slightly lobate aspect. 
The rhomboidal caudal fin, whose rays commence almost immedi- 
ately behind those of the second dorsal and anal, is perfectly symme- 
trical, the axis of the tapering extremity of the body being not only 
free from any upward inflexion, but corresponding with the “ equator ” 
of the fin. 
The scaly extremity of the body appears to stop at some distance 
before reaching the posterior margin of the fin, but it is difficult to 
make quite sure of the fact. 
The scales are thin, and exhibit a sculpture of variable appearance, 
but always made up of raised ridges, with intervening valleys and pits 
over the greater part of their surface ; narrow smooth facets being left 
along two sides to receive the overlapping edges of other scales. 
A single longitudinal row of hexagonal scales occupies the middle 
line of the back, and a less marked row of rhombic scales runs along 
VOL. II HH 
