62 TRIASSIC FISHES AND PLANTS. 
lar; clavicles coarsely plaited; bones of the head all granulated; scales rhom- 
boidal, smooth, those of the lateral line strongly marked, oblong, some- 
what rounded above and below, emarginate behind, showing conspicuous 
mucous pores or tubes; scales of the under side of the body very numerous, 
narrow, elongated longitudinally; pectoral and ventral fins small; dorsal fin 
opposite to or a little in advance of the anal; caudal fin forked; anal fin 
broad, rounded, consisting of twenty-two long and two short rays, of which 
the central ones are broadest and are supported by strong interspinous 
bones; anterior rays of all the fins set with short, oblique, obtuse, polished 
fulera. At the base of the caudal fin, above and below, these are succeeded 
by large, ovate, pointed, fuleral scales, which reach forward to the dorsal 
and anal fins. 
The type specimens of Dictyopyge were obtained by Sir Charles Lyell 
at Blackheath, Va., and were described by Sir Philip Egerton.’ This fish 
was previously described by W. C. Redfield under the name of Catopterus 
macrurus in the American Journal of Science, (vol. 41, 1841, p. 27), but Sir 
Philip Egerton, as cited by Lyell, considered it distinct from the genus Catop- 
terus, because ‘the dorsal fin is more strictly opposite to the anal than in 
Catopterus Redfield,” and because, ‘Shaving a homocereal tail, it can not be 
comprehended in it.” » Mr. Redfield did not accept the genus Dictyopyge of 
Egerton, because, as he said, Catopterus macrurus was really no less hetero- 
cereal than the other species of the genus, and with the other common char- 
acters the slight difference in the position of the fins had in his judgment only 
a specific value. There is something to be said on both sides of this ques- 
tion, and perhaps it cannot be settled until we have more material; but by a 
careful study of that now in hand I have been inclined to accept the genus 
Dictyopyge. In Catopterus macrurus of Redfield the opercula are larger, con- 
stituting one-half a circle, the scales of the under side of the body are much 
more numerous, the dorsal fin is more in advance, the anal fin broader, 
larger, and rounder, and the interhaemal spines by which it is supported 
are inuch stronger, and finally the tail is less forked than in the other species 
of Catopterus. In my specimens, as well as in those figured by Sir Philip 
Egerton, the dorsal fin is decidely in advance of the anal, and both are so 
'Quart. Jour. Geol. Soc, London, vol, 3, 1850, p. 275, 
