ACROLEPIS HOPKINSI. 109 
type species Acrolepis Sedgwicki from the Marl Slate, in which the Paleeoniscid contour 
is well shown. Fig. 2 represents the outer and fig. 3 the inner surface of a flank-scale 
of the same species magnified, showing the great breadth of the covered area and the 
extensive production upwards of the antero-superior angle, while fig. 4 is a similarly 
shaped but smaller scale. Fig. 5 shows the transverse jointing of portions of two dorsal 
fin-rays with the sculpture of the exposed surfaces of the joints. 
Species.—Vhe undoubted species of Acrolepis are Carboniferous and Permian, the 
best known species 4. Sedgwichki, Agass., and 4. exvsceulpta (Kurtze) being from the Marl 
Slate and Kupferschiefer (Upper Permian) of England and Germany, while the largest 
known is 4. gigas, A. Fritsch, from the Lower Permian of Bohemia. Doubtful species 
are 4. reticulata, Kichw., from the Old Red Sandstone of Orel, Russia ; Acrolepis (?) 
Drummondi, Traq., and Acrolepis (?) digitata, Smith Woodward, from the Karoo forma- 
tion of Africa. The British Carboniferous species to be here described are A. Hophinsi, 
M‘Coy, 4. semigranulosa, Vraq., A. ortholepis, Vraq., and A. Wilsoni, 'Traq.* 
1. AcrontePis Hopxinst, ‘Coy, sp. Plates XXIII, XXIV, and XXV, fig. 6. 
? Gyroteris Ranxtnet, Agassiz. Poiss. Foss., vol. i, pt. i, 1844, p. 8038 (name 
only). 
Honoprycurus Horxrysi, W‘Coy. Ann. Mag. Nat. Hist. [2], vol. ii, 1844, p. 2. 
Acroteris Hopkins, M‘Coy. Brit. Palwoz. Foss., 1855, p. 609, pl. ii—G, 
fie. 10. 
=e Traquair. Quart. Journ. Geol. Soc., vol. xxxii, 1877, 
p. 571. 
~- RanxIvet, Traquair. Ibid., p. 571. 
= Horxinst, Traquair. Proc. Roy. Soc. Edinb., vol. xvii, 1890, p. 398 ; 
and Cat. Carb. Fishes of West of Scotland 
in Brit. Assoc. Handbook, Glasgow Meeting, 
1901, p. 515. 
= — A. 8. Woodward. Cat. Foss. Fishes Brit. Mus., pt. ii, 
1891, p. 506. 
Specific Characters.—A large species, having the external head-hones mostly ridged, 
the ridges passing sometimes into tubercles ; scales having the exposed surface covered 
by well-marked sharp ridges, oblique and sub-parallel in direction, frequently inter- 
calated, less often branching, save on the caudal region, where they are sometimes 
reticulated. 
Description.—The original specimen from the Carboniferous Limestone of Derby- 
shire, described and figured by M‘Coy, consists of two somewhat fragmentary scales, the 
1 A fish from the Carboniferous of Carluke, Lanarkshire, is mentioned by Agassiz (‘ Poiss. Foss.,’ 
vol. ii, pt. ii, 1844, p. 162) under the name of Acrolepis acutirostris. No description was given, and 
nothing is known of the specimen. 
