OF THE COUNTIES OF NORTHUMBERLAND AND DURHAM. 233 
but they are alittle larger on the anterior part, and about as high 
as wide. ‘Their surface is nearly smooth, only a few strize are 
seen near the anterior side. The posterior margin is denticu- 
lated. Near the end of the tail the strie and denticulations 
gradually disappear, and completely fail on the little elongated 
scales which cover the upper lobe. It is to be remarked that 
the superior and inferior sides of the scales, especially those of 
the tail are straighter than their posterior side, while in the 
P. comtus they are sensibly arched.”—Ag. 
3. P. guapHyrus, Ag. 
Palconiscus glaphyrus, Ag., Poiss. Foss. ii., p. 98, pl. 10 ¢, 
ale: 
In the Marl-slate; rare. Ferryhill, Thickley. 
“The head of this fish is proportionally very small. It equals 
about one-fifth of the total length of the body, and is of less 
width than the trunk. The rays of the fins are more distant, 
and the bifurcations are less numerous than in the other species 
belonging to this genus, but they are very much jointed. The 
scales are proportionally very large on all the surface of the 
body. Their exterior surface is quite smooth, and their sides 
are straight ; the posterior side is distinguished by very distinct 
notchings. All the scales are very thin. The most characteristic 
features of this fish are its great scales and its short body.” —Ag. 
We have seen a fragment of a fish found by J. H. Fryer, Esq. 
in a laminated nodule of Magnesian-limestone, from Marsden 
Bay, which appears to belong to this species. 
4, P. tonaisstmus, Ag. 
Paleoniscus longissimus, Ag., Poiss. Foss. ii., p. 100, pl. 10c., 
f. 4. 
In Marl-slate ; rare. Ferryhill. 
“ This fish may be distinguished from all others of the genus, 
by its great length. The head equals about one-sixth of the 
whole length of the body. The fins are proportionally small, and 
owing to the great length of the body, they are very distant; the 
dorsal is opposed to the ventrals, and occupies the middle of the 
back. The anal fin is nearer to the tail than to the ventrals ; the 
fins are bifurcated about one-third of their length, and as 
