42 TRIASSIC FISHES AND PLANTS. 
other group is much broader, the body being sometimes two and a half 
inches high anterior to the dorsal fin. These were relatively flat fishes, while 
the others were cylindrical or fusiform. As we compare most of the mem- 
bers of the two groups they seem so unlike that no one would hesitate about 
considering them distinct species, but it is also true that there are interme- 
diate forms, which serve to connect these groups, and which are apparently 
as near to one as to the other. Hence it is not easy to define accurately 
either of the two species which W. C. Redfield has founded upon them. In 
most cases, however, there need be no doubt, the fusiform and slender fish 
standing for I. fultus, the broader one for I. macropterus. In my notes on 
Ischypterus fultus I have further discussed this question, and have shown 
how difficult it is to identify the species, which have been described very 
briefly from imperfect material, and where the type specimens have been lost 
sight. of. 
Another reason why we may suspect that the fishes combined by 
Agassiz and subsequently by Redfield under the name of J. fultus should 
be referred to two species, is found in their distribution. As remarked else- 
where, the individuals figured by Agassiz and taken as the types of his 
species fultus, are so imperfect that they cannot certainly be identified with 
any of the Triassic fishes obtained from the Connecticut Valley or from 
New Jersey. I have even suspected that they were only mutilated speci- 
mens of the most common speices, I. tenuiceps, found at Sunderland, where 
Agassiz’s fishes were obtained; but oceasionally a narrow, fusiform, and 
smaller fish is met with at Sunderland and Turner's Falls, which may be 
the same with those figured by Agassiz. Whether this is identical with 
any of the fishes found in New Jersey is yet uncertain, because the 
material we now have for comparison is inadequate; but if identical with 
either of the New Jersey forms it is with the narrower one, which was 
adopted by W. C. Redfield as the representative of the species J. fultus. 
Up to the present time none of the broader fishes which I have taken as 
representing Nedfield’s species or variety, Z. macropterus, have been found 
the Connecticut Valley; a fact which justifies the inference that these in 
closely allied forms are specifically distinct. 
pfeil, tent ha 
