18 RAMSAY H. TRAQUAIR’S 
DESCRIPTION OF GENERA AND SPECIES. 
Order GANOIDEI. 
Suborder ACANTHODEIL. 
Family ACANTHODID#. 
Genus Acanthodes, Agassiz, 1833. 
(Agassiz, Poissons Fossiles, vol. ii. p. 19.) 
Several imperfect specimens of Acanthodes have occurred in the Eskdale 
beds, but in the present unsatisfactory state of our knowledge of the British 
Carboniferous members of this genus, it may be safer to leave them for the 
present undetermined as to species. It is to be hoped that ere long the 
accumulation of more material, from various, horizons and localities, will render 
practicable a satisfactory revision of the Acanthodide of the Carboniferous 
formation generally. Meanwhile, the want of sufficiently definite characters 
for the species already named renders the determination of specimens, 
especially when in a fragmentary condition, a matter of extreme doubt and 
uncertainty. 
Suborder CROSSOPTERYGIL 
Family RuizopontTip&. 
Genus Strepsodus (Huxley), Young, 1866. 
A tooth undistinguishable from those of Strepsodus sauroides, Binney 
sp., has occurred at Tweeden Burn in Liddisdale, and another at Glencartholm 
in Eskdale. To Strepsodus may also be referred some large thin cycloidal 
scales from Glencartholm, one of which measures 12 inch in diameter. 
Strepsodus is of rare occurrence below the horizon of the Millstone Grit, 
and the present specimens occur lower down in the series than any which have 
hitherto been found. The remains of Strepsodus sauroides constitute, as is well 
known, abundant and characteristic fossils in the bituminous shales and 
cannel coals of the True Coal Measures both in England and Scotland. 
Genus Archichthys, Hancock and Atthey, 1871. 
Archichthys Portlock, Ag. sp. 
THoloptychius Portlockii, Agassiz, Poissons Fossiles, vol. i. pt. xxxvi.—name only. 
ry 5 Portlock, Geol. Rep. p. 464, pl. xiii. figs. 5-11. 
M‘Coy, in his “ British Paleozoic Fossils,” p. 613, states that he is quite 
certain “that the Holoptychius Portlockii (Ag.) of the fish beds at Cultra 
Holywood, near Belfast, and Draperstown, &c., are identical in all characters, 
both of the teeth and scales, with the Holoptychius Hibberti (Rhizodus) of 
the Burdiehouse and Gilmerton beds.” However, in his list of synonyms of 
