74 TRIASSIC FISHES AND PLANTS. 
acute, as is shown in several specimens in my possession. The teeth of 
Holophagus can hardly be said to be known; those of Undina are stated by 
Count Miinster and by Professor Huxley! to be pavement-like and tuber- 
culated; finally, those of Macropoma are conical and acyite. 
DipLurvus Loneicaupatus Newb. 
Pl; XX, Figs. 1-5. 
Diplurus longicaudatus Newb., Annals New York Acad. Sci., vol. 1, p. 127. 
Fish attaining a length of three feet and a breadth of eight or ten 
inches; body fusiform, symmetrical; head pointed, sloping rapidly down 
from the occiput; back gently arched, anterior dorsal fin strong, sup- 
ported by a semicircular bone; posterior dorsal placed nearly opposite to 
the anal fin and midway between the anterior dorsal and the extremity of 
the body; caudal fin very long, supported by thirty-two ? long and strong 
rays, which are spliced on to the interneural and interhamal spines ; 
supplemental caudal separated from the caudal fin by a distinct interval ; 
in form it is an equilateral triangle about three inches on a side; the web 
of this fin is supported by about nine simple fluted rays above and below, 
of which the bulbous bases were inserted into the cartilaginous extremity 
of the vertebral column, as posts are set in the ground; paived fins 
strongly lobate; anterior fin rays of these and the two dorsal fins 
roughened by many short, conical, acute spines; teeth unknown; scales 
ovoid, half an inch in diameter, the exposed portion occupied by fine 
parallel raised lines, running from front to rear. 
Only four specimens and the head of a fifth have yet been found of 
this the largest of our Triassic ganoids, and all these are now in the Geo- 
logical Museum of Columbia College. Two of these specimens were 
obtained in excavations made at Boonton, N. J.; the others were collected 
by 8. W. Loper at Durham, Conn. 
The smaller of the Boonton specimens is figured on Pl. XX of this 
memoir. This is interesting, as showing the general form of the fish, the 
position of the fins, ete., but the details of structure are not distinctly per- 
ceptible. Another and much larger specimen was found at Boonton, but it 
1Mem, Geol. Survey, United Kingdom, British Organic Remains, Decade 10, 1861, p. 17, 
eA BS iw, 
