850 Messrs. Hancock & Atthey on Reptile- and Fish-Remains 
In all respects our specimens agree well with Dr. Young’s 
description of this species in the ‘Journ. Geol. Soe.’ (loc. 
cit.). ‘The scales are usually well preserved; all the fins, as 
well as the tail, can be determined; and the gill-opercles, 
mandibles, and upper jaws, in a more or less entire state, with 
the teeth attached, are all displayed. 
The scales vary, of course, greatly in size; on the smallest 
fish they cannot be more than a quarter of an inch long, while 
large detached scales measure an inch in length. They are 
all, however, so perfectly similar that it is impossible to deny 
their specific identity. The coarseness of the surface-sculp- 
ture and the thickness of the scale vary, as might be expected, 
with its size; but no other difference can be detected. It is 
therefore only left us to follow the prudent caution of Dr. 
Young, and to wait for further information before doing any- 
thing so rash as to divide specifically the thin and delicate 
from the thick and comparatively coarse scales. There is one 
character, however, which seems to have escaped the notice of 
this paleontologist, and which is pretty distinct in one or two 
of our examples. ‘The dorsal and ventral fins are protected in 
front by a series of thick enamelled scales, which are brilliantly 
glossy and minutely punctured, not at all like the body-scales, 
but similar to those in front of the fins, in Megalichthys. The 
first or proximal scale is very stout, if not a solid cylinder, and 
is three-quarters of an inch Cenk it looks almost like the base 
of a spine, but is probably composed of two lateral plates. 
This is succeeded by a double longitudinal series of elongated 
rectangular pieces, which extend apparently almost to the 
distal margin of the fin. 
The premaxillary bones, which were wanting in Dr. Young’s 
specimens, are present in some of ours; and they, as well as 
the mandibles, have a large, slightly curved laniary tooth at 
the distal extremity. This is succeeded by a series of numerous 
small conical teeth, of the same size and character as those of 
the maxilla. These, as well as the small mandibular teeth, 
are placed at pretty regular intervals, though it is not uncom- 
mon to observe two or three pressed close together. Traces of 
two or three additional laniary teeth can be observed in the 
mandibles, situated on a line a little within the row of smaller 
teeth. 
The premaxillary bone is unusually long; the maxilla is 
shorter than the former, and is narrow in front and expanded 
considerably behind. ‘The mandibles are long, narrow bones, 
with the margins nearly parallel and the distal extremity — 
rounded. The surface of all these bones is rugose, with irre- 
gular reticulated ridges or wrinkles and punctures. 
