112 GANOID FISHES OF THE CARBONIFEROUS FORMATION, 
‘The type is from the Carboniferous Limestone of Derbyshire and is contained in the 
Woodwardian Museum, Cambridge. 
2, ACROLEPIS SEMIGRANULOSA, Traquair. Plate XXV, figs. 9—11. 
ACROLEPIS SHMIGRANULOSUS, Traquair. Proc. Roy. Soc. Edinb., vol. xvii, 1890, 
p. 398. 
— SEMIGRANULOSA, A. 8. Woodward. Cat. Foss. Fishes Brit. Mus., pt. 
ii, 1891, p. 507. 
Specifie Characters.—Exposed surface of scales covered with innumerable closely set 
fine ridges, wavy and often tortuous, and tending at places to break up into minute 
tubercles. 
Description.—The only specimen which has occurred hitherto is a patch of confused 
scales ten inches in length by four in greatest breadth, and including at one extremity 
a fragment apparently of one of the plates of the head. ‘These scales are mostly flank- 
scales and are all more or less broken, the most entire one being the ventral scale repre- 
sented in fig. 11. The covered area of the flank-scales (figs. 9 and 10) is extensive and 
passes upwards into a prominent pointed process; the exposed area has its antero- 
superior angle concavely truncated; the whole of this free surface is covered with fine, 
closely set ridges or stria, wavy and often tortuous, bifurcating and interrupted, and 
tending in places to break up into minute tubercles, the main direction of these strize 
passing in some cases (figs. 10 and 11) transversely or obliquely across the scale from 
back to front or in other cases (fig. 9) mainly vertically from above downwards. The 
scale represented in fig. 11, evidently a ventral scale, has its covered area produced 
obliquely upwards and forwards in a long, slightly curved pointed process, the length of 
which is more than twice the height of the free area of the scale. I can see no trace of 
denticulations along the posterior border of any of the scales shown in the specimen. 
On the fragment of a large cephalic plate included in the specimen, the ornament 
consists entirely of minute and closely placed tubercles or granulations. 
Observations.—That the scales described above belonged to a fish of the genus 
Acrolepis is, | think, perfectly evident from their shape, and their specific distinction is 
equally clear from their peculiar ornament, consisting as it does partly of very fine strize 
and partly of minute tubercles. 
Geological Position and Locality.—Lower Carboniferous. ‘lhe above described 
unique specimen is in the Royal Scottish Museum, Edinburgh, and occurred in the 
“ Dunnet”’ Shale, formerly worked at Straiton near Burdiehouse, Midlothian. 
