66 TRIASSIC FISHES AND PLANTS. 
four inches long; most of them being about six inches long by one and a 
quarter inches wide. Possibly these specimens represent more than one 
species, but the material yet found scarcely suffices for the accurate defini- 
tion of more than one, and it is quite possible that the differences they 
exhibit are only those of age. I give below the detailed description of this 
species taken with slight modification, from the paper referred to above. 
‘Prycnotepis Marsui Newb. 
Pl. XIX, Figs. 1, 2, 2a. 
Fish eight inches or more in length by two and a quarter in breadth, 
fusiform, robust; head pointed, contained four and a half times in the en- 
tire length; all the bones of the head marked with strong raised lines, those 
of the upper surface somewhat radiate; on the opercula, maxillaries, man- 
dibles, and gular plates more or less undulately parallel and forked. The 
dorsal fin is of medium size and placed near the center of the back; the 
anal is set far back, reaching nearly to the caudal; caudal small, forked, 
the scales and vertebral column reaching distinctly into the upper lobe. 
The scales on the anterior portion of the body are two or three times as 
long as high, and are marked with several longitudinal furrows and raised 
lines, In the middle and posterior portions they are five or six times as 
long as high, and are traversed by a superficial furrow, which generally 
reaches from the anterior end half or two-thirds’ the length and is again 
resumed on the posterior margin; by this the extremities of the scales are 
forked. On the anterior portion of the abdominal surface the scales are 
exceedingly narrow, acute, and spine-like. Vertebral column partially 
ossified. 
On comparing our fish with the figure and description of P. Bollensis 
Ag. it will be seen that it differs from that species in the position of the 
dorsal fin (which is placed more anteriorly), in the details of the scales and 
head markings, and in the greater degree to which the tail is vertebrated 
and the spinal column ossified. In P. Bollensis the scales are covered with 
fine, simple, parallel ridges of enamel, but in P. Marshii the ridges are 
broader, fewer, and are forked. From P. minor Egerton our species is 
easily distinguished by its greater size, narrower and notched scales, and 
