14G GANOID FISHES OF THE CARBONIFEROUS FORMATION. 



account the sculpture of the scales, the smalluess of the fins, and the general proportions 

 of the fish. 



Geological Position and LocalHy. — From the Coal Measures, Jarrow Colliery, Co. 

 Kilkenny, Ireland. 



9. Rhadinicuthys macrodon, Traqiiair. Plate XXXII, figs. 3 — 5. 



KiiADiNiciiTUTS MACRODON, Traquaiv. Geo!. Mag. [3], vol. iii, 188(5, p. 441. 



— — J. Ward. Trans. N. Staffs. Inst. Mining Engin., vol. x, 



1890, p. 177. 



— — A. S. Woochvaril. Cat. Foss. Fishes Brit. Miis., pt. ii, 



1891, p. 4G9. 



— — E. D. Wellhurii. Proc. Yorks. Geol. and Polyt. Soc, 



1907, pp. 168 and 174. 



Specific Characfers. — Laniaiy teeth of unusually huge size; flank-scales covered 

 with delicate ridges and furrows, which run nearly parallel with the upper and lower 

 margins of the scale, though they tend to turn upwards anteriorly ; posterior margin 

 shai-jjly and prominently denticulated. 



Description. — The specimen (PI. XXXII, fig. 3) upon which this species is 

 founded measures 5 inches in length, but it is broken off just behind the commencement 

 of the caudal fin, as indicated by the dorsal ridge-scales; the length of the head is 

 ]|- inches, and the depth of the body nowhere exceeds I inch. Consequently the 

 general aspect is that of a fish of slender form, but the specimen cannot be relied on as 

 showing the original shape, as the scales are broken up and confused, and the fin-rays 

 almost entirely wanting. The head exhibits the typical Palseoniscid structure — the 

 suspensorium being very oblique, the gape wide, and the usual arrangement of opercular 

 and branchiostegal plates being shown ; the bones are, however, seen almost exclusively 

 from their internal surfaces. Both jaws are armed with stout, conical, incurved teeth of 

 unusually large proportional size, those of the maxilla measuring y^s to -^-q inch in 

 length ; the small external teeth are not visible. The scales are of comparatively large 

 size, those of the anterior part of tiie flank (fig. 5) having their exposed areas covered 

 with delicate ridges and furrows, which are nearly parallel with the upper and lower 

 margins of the scale, though they tend to turn upwards anteriorly ; the j)osterior 

 margin is sharply and prominently denticulated. As we proceed backwards the scales 

 lose the sharpness of their ornament, and become nearly smooth towards the tail, 

 though the caudal V-scales remain prominently striated. The origin of the pectoral 

 fin is present (fig. 3), though not well shown, and here the principal rays seem 

 unarticidated. A few broken-up ray-joints mark the position of the dorsal and anal 

 fins, the former occurring 3 inches, the latter 3f inches behind the front of the head. 



