CYCLOPTYCHIUS CARBONARIUS. 121 
Genus—CycLorrycuius, Young, 1866. 
Generic Characters.—Form narrow and elongated; suspensorium oblique and gape 
wide ; dentition of the normal Palaoniscid type, the teeth being conical, sharp, and 
enamel-capped, and of two sizes, an inner set of larger teeth being present along with 
an outer series of smaller ones. Scales rhombic, their postero-inferior angles tending to 
be rounded off; sculpture consisting of ridges with a more or Jess concentric arrangement. 
Pectoral fin having its principal rays unarticulated till towards their terminations ; ventral 
placed midway between the pectorals and the anal ; dorsal fin situated nearly opposite the 
anal, both being triangular-acuminate ; caudal heterocercal, deeply cleft and inequilobate ; 
fulcra on all the fins distinct. 
Cycloptychius resembles Rhadinichthys in many points, but is amply distinguished by 
the form and mode of sculpture of the scales and by the still more backward position of 
the dorsal fin. | Only two species are known, one from the Upper, the other from the 
Lower Carboniferous rocks of Great Britain. 
]. CycLoprycuius carBonarius, Young. Plate XXVII, figs. 1—5; Text-figure 5. 
CyYcLorrycHIiUs carBonartius, J. Young (exw Huxley MS.). Rep. Brit. Assoc. for 
1865 (1866), p. 319. 
Cycnorrycutus, Hancock and Atthey. Aun. Mag. Nat. Hist. [4], vol. i, 1868, p. 
362, 
— carbonarius, 7. P. Barkas. Coal Meas. Paleontology, 1873, 
p. 36, fig. 140. 
= _— Traquair, Geol. Mag. [2], vol. i, 1874, p. 241, 
pl. xii. 
— == Ward. Proc. N. Staffs. Nat. Field Club, 1875, p. 
240. 
~- W. J. Barkas. Monthly Rey. Dental Surgery, vol. i, 1875, p. 
500, figs. Ixvili—lxx. 
— caRBONARIUS, Ward. Trans. N. Staffs. Inst. Mining Engineers, 
vol. x, 1890, p. 179, pl. iv, figs. 3—5. 
— a A. S. Woodward. Cat. Foss. Fishes Brit. Mus., 
pt. 1, 1891, p. 460. 
Specific Characters.—Scales rhombic, with rounded postero-inferior angle; ridges 
fine, thread-like ; one of the ridges running along the upper part of the posterior margin 
is generally more or less zigzagged, so as to give almost a crenulated aspect to that 
margin. 
Description—Vhe following description is taken from specimens from the ‘“ Deep 
mine” Ironstone shale of North Staffordshire collected by the late Mr. John Ward, and 
now in the British Museum. All the specimens but one are the remains of small fishes, 
