263 
of Edinburgh, Session 1876 - 77 . 
cimen lies compressed on its back, and shows the under surface of 
the head, both pectoral and both ventral fins, with traces also of 
the dorsal, anal, and caudal. Its length is 9J inches, but the fish 
must originally have been a little longer, as its caudal extremity is 
imperfect. 
The scales are very small, and much disarranged, as. is the case 
in nearly all the fishes occurring in the same bed, but their confi- 
guration is apparently the same as in N. Greenochii , and their ex- 
ternal ornamentation consists, as in that species, of very fine oblique, 
thread-like, branching, and anastomising ridges; the median ridge- 
scales, extending from behind the dorsal fin along the upper margin 
of the caudal body- prolongation, are very large and pronounced. 
The bones of the head are much crushed and broken, so that only 
a few of them can be made out. The suspensorium is very oblique 
and the gape extensive, the length of the lower jaw being, in the 
first mentioned specimen, inch. The external surface of the 
lower jaw is ornamented with a minute and very close tubercula- 
tion; the dental margin of the maxilla is also tuberculated, but the 
rest of its surface is marked with delicate ridges, which run for the 
most part parallel with its superior and posterior margins. Large 
conical teeth occur in both jaws, with a few of the external series 
of smaller ones. One of the larger teeth in the mandible of speci- 
men No. 2 measures a little over J inch in length by — in diameter 
at the base; its form is regularly and acutely conical, with well- 
marked smooth enamel-cap at the apex, below which the surface 
is delicately and beautifully striated, the striae being more pro- 
nounced than is usually the case in N. Greenochii. The opercular 
bones are not visible, but some of the branchiostegal rays may be 
detected ; their outer surfaces are ornamented by very fine flexuous 
ridges. The paired fins are moderate in size; indeed Jhey might 
safely be termed small. The pectoral of No. 1 measures one inch 
in length ; in neither specimen can its number of rays be ascer- 
tained, but it is evident that the principal ones were unarticulated 
for about ^ of their length. Tire length of the ventral in the first 
specimen is § inch ; its rays, probably 25 in number, are delicate, 
smooth, and with their transverse articulations rather far apart. 
The dorsal and anal fins resemble each other in form, but the latter 
is apparently slightly the larger; both are triangular, acuminate, 
