36 TRIASSIC FISHES AND PLANTS. 
The fish represented on Pl. VI, Fig. 2, is perhaps a fair example of 
the species so common at Boonton, and which W. C. Redfield first described 
as Palceoniscus macropterus. He afterward suppressed that name in deference 
to Agassiz’s opinion that it was not different from those to which he had 
given the name P. fultus. Pl. VII, Fig. 1, represents a smaller fish, of 
which I have a large number of specimens, but I have considered these the 
young of the larger form referred to above. 
IscHYPTERUS ROBUSTUS, Nn. Sp. 
Pl. VI, Fig. 1. 
Fishes of medium or large size, eight inches or more in length by three 
in breadth anterior to the dorsal fin; outline ovoid; head large, narrowed, 
muzzle produced; dorsal fin very large, its anterior margin about the middle 
of the entire length and nearly twice as far from the posterior scaled ex- 
tremity of the body as from the head; fulera very numerous, strong, curved ; 
rays eleven, very strong; caudal fin of moderate size, upper lobe longest; 
anal of moderate size; ventrals inserted nearly opposite anterior margin of 
dorsal; pectoral fins relatively long and broad; scales of dorsal line long, 
forming a prominent crest; those of sides broad and thick. 
This is a robust and coarsely organized fish, most nearly allied to 
Ischypterus ovatus of Redfield, but distinguished by the great height, 
breadth, and strength of the dorsal fin and its anterior position. The pec- 
toral fins are also longer and broader than in any other species that I have 
seen, The ventrals and anal are not well shown in the specimens before 
me, but are apparently delicate; the caudal is relatively narrow, the lower 
lobe nearly horizontal, the upper strongly elevated and produced. 
The great height and breadth of the dorsal fin of this species bring it 
closer to Semonotus than any other of its congeners, and there is little doubt 
that if it had been found in the Mesozoic rocks of the Old World it would 
have been referred to that genus; indeed, it is now difficult to say by what 
characters it could be distinguished generically from some of the described 
species of Semionotus. The line of spine-like dorsal scales is somewhat more 
conspicuous, but this is only a matter of detail, since something of the kind 
is seen in all the species of that genus with which I have compared it. 
