FOSSIL FISHES. 35 
are most apparent on the posterior edge; scales of the dorsal ridge pointed and erect- 
ile, but in a much less degree than in Ischypterus tenuiceps; pectoral fins small, narrow, 
and pointed; ventrals small, very narrow, and pointed; dorsal and anal fins both very 
long, with the anterior raylets very strong and rather numerous; primary rays of anal 
about seven, slender; anterior raylets about twelve, anterior raylets of dorsal about 
fourteen ; tail forked, lobes more acute than in P. tenwiceps; accessary raylets long 
and numerous; length five to seven inches, breadth one and a half to two and a quarter 
inches. The specimens from which Agassiz constituted his Palwoniscus fultus were 
so imperfect, that it is difficult to decide with certainty which of our specimens should 
be referred to it. The character which he seized upon as its chief diagnostic, and on 
which he founded its specific name, /ultus, viz, the extraordinary size of the anterior 
raylets of the fins, exists in all the known American species of this genus. We are 
not at all sure that we have rightly referred P. macropterus of W. C. R. to this species; 
for the specimens figured by Agassiz are represented with dorsal and anal fins which 
are far from having the length of these fins in P. macropterus. Those specimens were 
evidently imperfect, and it is well known how easily the frail and carbonaceous rem- 
nants of rays are detached from these fossils, sometimes leaving hardly a trace behind, 
and it is very possible that these portions were broken in the specimens which were 
figured by Agassiz. His nameof P. fultus should in justice to him be retained, and 
since the long-pointed fins of the fish we have described above, strengthened as they 
are by large anterior raylets, will render the term fullus quite applicable, we think it 
advisable to restrict Agassiz’s name to this species, and suppress P. macropterus, This 
species is characterized by the length of the dorsal and anal fins, which are even longer 
than in P. tenuiceps, from which species it is also readily distinguished by its form, the 
back not suddenly rising from the head as in that. 
Among the fishes left by W. C. Redfield I find many which are labeled 
Ischypterus fultus. Most of these are from Boonton, and it is repre- 
sented by him as the most common species found there. The form is 
rather narrow, the length from six to eight inches, the breadth never more 
than two inches at the widest part, which is half way between the dorsal fin 
and the head; the fins are relatively large; the tail is scarcely forked, but 
rather scalloped, with a broad and shallow sinus; the head is depressed, 
longer than wide, and about one-sixth of the entire length. From Durham 
and Sunderland [ have specimens which I suppose must represent the fish 
named P. fultus by Agassiz, for his specimens were derived from the latter 
place. They are smaller than those from New Jersey, not over six inches 
in length by one anda quarter inches in breadth. It is quite possible that 
they represent a different species from that so common at Boonton, but that 
can only be shown by more extensive comparisons than I have been able to 
make, 
