64 TRIASSIC FISHES AND PLANTS. 
the dorsal fin is exactly opposite the anal, while in the latter the first rays 
of the dorsal are opposite the middle of the anal, but in another species of 
Catopterus (C. minor N.) the position of the fins is exactly that of D. socialis ; 
while in the Virginia species, which was taken by Egerton as the type of his 
genus Dictyopyge, the dorsal fin is sensibly anterior to the anal; so that this 
character can not be considered as diagnostic. Another distinction which’ 
Striiver makes between Catopterus macrurus (which he erroneously names 
macropterus throughout his article) and Dictyopyge socialis, viz. “ fulera der 
Schwanzflossen ziemlich gross” and ‘“fulcra sammtlicher Flossen fein,” does 
not hold good, for the fulcra are quite as fine in the Virginia as in the Co- 
burg specimens. The only differences which I can specify between our 
commonest species of Catopterus and Dictyopyge socialis are the broader 
operculum, the narrower scales of the belly, and the less deeply forked tail 
of the latter. In these characters Dictyopyge macrurus and D. socialis are dis- 
tinguished from all the species of Catopterus found in New Jersey or in 
Connecticut; and, as I have said elsewhere, these may perhaps afford a 
raison d’étre for Dictyopyge. 
DictyopyGe MacrurA Egerton. 
Pl, XVIL, Figs. 1, 2. 
Catopterus macrurus W.C. R., Am. Jour. Sci., vol. 41, 1841, p. 27. 
Dictyopyge macrura Egerton, Quart. Jour. Geol. Soc., London, vol. 6, 1850, p. 4. 
Fishes small, fusiform; head rather small, surface finely granulated; scales of 
medium size, those of the sides and back square or slightly rhomboidal, those on the 
under side of body very numerous and narrow; pectoral fins of medium size, primary 
rays seven or eight, anterior raylets very fine, short, and close, over forty in number; 
ventrals small, triangular, and elongated, rays eight or nine, fulera about thirty; anal 
very large, quadrate, sometimes reaching as far as base of caudal, rays over thirty in 
number; tail forked, very long, acute, and spreading, lower lobe longest, rays thirty- 
five to forty, closely articulated and toward the extremity finely subdivided. Length 
five inches, breadth one and a quarter inches. 
The above description is abbreviated from that of J. H, Redfield. Fur- 
ther details will be found in the discussion of the generic relations. 
Up to the present time no specimens of this fish have been found else- 
where than in the Richmond coal basin. There it is locally very abun- 
