116 GANOID FISHES OF 'THE CARBONIFEROUS FORMATION. 
margins respectively. ‘I'he surface between the pits is minutely fretted with excessively 
delicate grooves which are only perceptible by aid of alens. ‘The well-developed covered 
area projects upwards in an angular process ; the articular spine is well developed. 
Observations.—The original specimen was recognised as new by the late Mr. J. Ward 
of Longton, who passed it on to me for description with the request that I would name 
it after its finder, Mr. E. Wilson, F.G.S. Since that time it has come into the possession 
of the British Museum, as have likewise the specimens here figured. ‘The shape of these 
scales indicates Acrolepis as the genus, and the peculiarity of their markings is such as to 
entitle the fish to which they belonged to most unmistakable specific distinction. 
Geological Position and Locality—lrom the Yoredale Series of ‘Turnditch near 
Belper, Derbyshire. 
ye 
Genus—N wmatorprycuius, Zraguair, 1879. 
1844. Pyaorrerus, Agassiz (pars). 
1875. Nemarortycutus, Traquair. 
Generic Characters.—Geueral form elongated; suspensorium very oblique; gape 
wide; teeth sharply conical, enamel-capped, of different sizes, large and small, the large 
ones forming a row internal to the more numerous and closely placed small ones. Vlank- 
scales much higher than broad, with a flat triangular articular process arising from the 
whole or nearly the whole of the upper margin ; antero-superior and postero-inferior 
angles of the exposed surface of the scale obtuse ; covered area of scale extremely narrow ; 
ornament of exposed surface consisting of fine, closely set thread-like ridges; paired fins 
moderate in size; principal rays of pectoral unarticulated for some slight distance from 
their origin; ventral fin situated rather nearer to the anal than to the pectoral, its base 
not elongated. Dorsal fin situated far back, nearly opposite the anal ; both are triangular- 
acuminate ; caudal powerful, deeply bifurcated. Marginal fulcra on all the fins very 
distinct but small. 
The form of the scales, with the backward position of the dorsal fin, is characteristic 
for the genus, of which only one species is as yet known. 
Nematoprycuius Greenockt, Zraguair. Plate [, figs. 7—11; Plate XXVI. 
PyGorrERUS GREENOCKII, Agassiz. Poiss. Foss., vol. ii, pt. ii, 1844, p. 78 
(undefined). 
— — Traquair. Proc. Roy. Soe. Edinb., vol. v, 1866, p. 
597. 
— — Traquair, Trans. Roy. Soc. Edinb., vol. xxiv, 1867, 
p (OL; pl. xv. 
== ELEGANS, C. W. Peach. Rep. Brit. Assoc., 1871 (1872), Trans. 
Sect., p. 109 (name only). 
