144 GANOID FISHES OV THE CAUBONIFEROUS FORMATION. 



The opercular bones arc rather small, the jaws j)rctty stout ; the dentition is 

 not visible. Tiic bones of the cranial roof are sculptured with contorted and lather 

 flattened ruga^j those of the face are ornamented with sharp and closely set, wavy ridges, 

 which, on the opeiculuni, ])ass obliquely downwards and backwards over its surface. The 

 scales are of moderate, one nn'ght almost say small, dimensions, and though, of course, 

 gradually diminishing towards the tail, those on the flanks are not marked by any very 

 special excess in size. The flank-scales are nearly equilateral; the ])Osterior margin of 

 each shows five or six prominent oblique denticulations ; the outer surface shows a few 

 feebly marked, nearly obsolete ridges passing obliquely backwards and a little down- 

 wards, and not very regularly placed. Immediately behind the clavicle and above the 

 origin of the ))ectoral fin the sculpture is, however, more strongly pronounced, the ridges 

 being finer, sharper, and closer together, but posteriorly the scales soon become nearly 

 smooth. The paired fins are rather small; the principal rays of the pectoral are 

 clearly seen to be unarticulated till towards their terminations ; the ventrals are 

 situated midway between the pectorals and the commencement of the anal ; their rays are 

 delicate and distantly jointed. The dorsal and anal fins are large and situated nearly 

 opposite each other, the former commencing slightly in front of the latter, as is usual in 

 the jienus. Both have the same form, beino- liioli and acuminate in front and concavelv 

 cut out behind : their ravs are rather coarser than those of the ventrals and their 

 articulations distant. The distance between the commencement of the lower lobe of the 

 caudal and the termination of the base of the anal, is less than the length of the base of 

 the latter. The caudal fin is usually imperfectly preserved, as in figs. 7 and 9 ; 

 however, it is pretty well seen in fig. 8 — the prolongation of the body-axis in the upper 

 lobe being delicate, the rays slender and with delicate articulations. 



Geological Post/ion and Localities. — The type specimens are from Wardie Beach, 

 near Edinburgh, but I cannot separate from them fishes more or less entire which have 

 been collected at Pitcorthy, in Fifeshire, and Gullane, in East Lothian — two examples 

 from the last-named locality being here figured (Pi. XXXI, figs. 8 and 9). The species 

 is as yet only known from the Calciferous Sandstone Series. 



8. Rhadiniohthys HiBiiRNicus, Tvoquair, sp. nov. Plate XXXII, figs. 1, 2. 



Specific Characters. — Attaining a length of between 6 and 7 inches ; length of 

 head contained four and two-thirds times in the total; fins small; dorsal situated 

 almost exactly opposite anal ; scales sculptured with fine, closely set ridges, 

 branchino- intercalated and wavv, but on the whole followino; a transverse direction 

 parallel with the superior and inferior margins, and apparently ending in fine denticu- 

 lations of the posterior margin. 



Description. — The length of the unique specinien is G|^ inches ; the length of the head, 

 which is about equal to the depth of the body, is contained four and two-thirds in the 



