439 
of Edinburgh, Session 1876 - 77 . 
rather large, being contained about 4 times in the total. The 
cranial bones are beautifully ornamented with delicate wavy ridges, 
running mostly in a longitudinal direction. The jaws are armed 
with sharp conical teeth of different sizes. The scales are of mode- 
rate size, gradually diminishing posteriorly, though those on the 
flanks are not of specially large dimensions. The flank scales are 
nearly equilateral in shape ; the free surface of each is ornamented 
with 5 or 6 pretty well-marked oblique ridges, running downwards 
and backwards, and terminating in the denticulations of the pos- 
terior margin. Eelow there are a few more delicate striae parallel 
with the lower margin. Along the back, between the head and the 
dorsal fin, the scales are smaller, and the ornamentation takes the 
form of a few sharply-marked striae passing diagonally across the 
scale between the two acute angles. Posteriorly, as the scales 
become smaller, the ridges are fewer, and the ornamentation becomes 
more and more feebly marked, till on the tail pedicle the scales are 
nearly smooth, and entirely so on the caudal body prolongation, 
which is delicate. Some amount of individual variation occurs in 
the scales of different specimens, which I see no good reason for 
referring to different species. In two fragments representing 
portions of rather larger fishes than the rest, the scales of the back, 
between the head and the dorsal fin, are rather smoother, while 
those of the flank show a greater number of ridges and denticula- 
tions of the hinder margin ; on the other hand, in the smallest 
specimen of the series, the ridging on the dorsal scales is very well 
marked, and rather feeble in those of the flanks. 
The pectoral fin is shown in one specimen, but not well, being a 
little obscured by a thin film of the matrix ; the ventrals are visible 
in none. The dorsal and anal fins are situated nearly opposite each 
other, the anal commencing only a little further back. The entire 
contour of these fins is not clearly exhibited, but their rays are 
smooth, delicate, and slender, with distant transverse articulations, 
The caudal is inequilobate, its rays are likewise delicate and smooth, 
and with distant articulations; the caudal body prolongation is 
slender. 
Remarks . — In its general proportions R. Geikiei is not so slender 
as most species of the genus, and there is not the usual interval 
between the anal and caudal fins ; in these respects it agrees with 
