26 RAMSAY H, TRAQUAIR’S 
elevated ridges, which, although wavy and sometimes contorted, mainly follow 
a longitudinal direction, especially on the parietal and frontal plates and the 
posterior part of the superethmoidal; they are often bifurcated, intercalated, and 
interrupted, and on the lateral parts of the cranial shield these interruptions 
often become so frequent as to cause the ornament to assume a somewhat 
tubercular character ; in some specimens this condition invades even the more 
central parts. On the anterior part of the superethmoidal, which forms the 
usual projection over the mouth, the ridges are disposed transversely, or at 
right angles to those behind. 
The direction of the suspensorium is very oblique, and the gape conse- 
quently wide. The opercular bones are well developed, and of the usual shape 
in this genus, but their external markings are not distinctly preserved. The 
maxilla has its broad portion ornamented with fine ridges, which run parallel 
with its superior and posterior margins; its infra-orbital process is tubercu- 
lated, and the tubercles are continued backwards as a narrow band along the 
entire inferior or dentary margin of the bone. The beautifully tapering 
mandible is covered externally with fine ridges, which pass forward from the 
angle in a somewhat radiating manner, so that below they are pretty parallel 
with the inferior margin, while above they cut the superior one at low angles. 
In large specimens these ridges break up into a minute tuberculation along the 
superior margin of the jaw—a condition rarely met with in the smaller 
examples. The orbit is anteriorly placed, and furnished with the usual arrange- 
ment of suborbital and circumorbital plates. 
The bones of the shoulder girdle are ornamented with well-defined sub- 
parallel ridges, which are arranged according to the common pattern, namely, 
somewhat concentrically, and more or less parallel with the margins of the 
bones. 3 
The scales are of moderate size, with narrow covered area, rhomboidal in 
shape, and increasing in obliquity, and diminishing in size towards the tail. 
On the flanks they are tolerably equilateral, but along the belly between the 
pectoral fins and the posterior part of the base of the anal, they suddenly 
become very low and narrow, their height diminishing to from } to } of their 
length. This change of form usually occurs at the fourth or fifth scale down- 
wards from the lateral line. A few large scales are seen in front of the dorsal 
anal, and lower lobe of the caudal fin, and on the body-prolongation in the 
upper lobe of the latter the usual modifications of shape occur. 
As regards the scale-markings, their general plan may be described as 
follows :—Taking a scale from the anterior part of the flank (figs. 15, 16), a few 
delicate grooves are seen passing down along the anterior margin of the ganoid 
area, Which then turn round at the anterior inferior angle so as to become 
parallel with the inferior margin. The rest of the area presents, according to 
