RHADINICHTHYS L/EViS. 149 



The species has also been recorded by Mr. E. D. Wellbiirn from the " Better Bed " 

 Coal, Low Moor, Yorkshire. 



11. Rhauiniuhthys i./evis, Traqnair, sp. iiov. Plate XXXIII, figs. 3 — 6. 



Specific CViaracfers.— Scales smooth, except iiDinediately behind the shoulder-girdle; 

 posterior margin of the scales mostly free from denticulation ; maxilla and dentary bone 

 of mandible finely tubercnlated, except a narrow band along the lower margin of the 

 latter, which is longitudinally striated. 



Descriptio7i. — The length of the specimen as it lies is 4^ inches — the original length, 

 if we allow for deficiency of snout and caudal extremity, would not be under 5 inches. 

 The form of the fish (PI. XXXIIl, fig. 3) is rather deeply fusiform, the greatest depth 

 of the body being contained a trifle over four times in the estimated total length. The 

 head is shown in impression only ; the snout is deficient, and what is setn of the imprint 

 of the posterior part of the cranial roof shows that it had externally a tubercnlated 

 ornament. The impression of the opercular bones is not visible, but those of the maxilla 

 and mandible (fig. 4) stand out clearly, and show, first, that the maxilla was finely and 

 closely tubercnlated ; and second, that the dentary of the mandible was similarly 

 ornamented, excepting a narrow band along the inferior margin, which was finely and 

 longitudinally striated. 



The scales are of moderate size, rhonjbic, and, so far as can be seen, for the most 

 part free from denticulation of the hinder margin. Some few denticulations arc, how- 

 ever, occasionally seen on the flank-scales, as in the one represented in fig. 5. All 

 over the body they are smooth, excepting only a very limited space immediately behind 

 the shoulder-girdle, where the impressions give evidence that here the surface was 

 ornamented with well-defined ridges passing obliquely downwards and backwards. 

 Fig. G represents one of the scales near the caudal extremity of the body. 



Traces of the pectoral fin are seen immediately behind the jaws, and, so far as can 

 be seen, they conform to the BhadinichtJii/s-iy\)Q in being unarticulated till towards their 

 terminations. The ventrals are not shown, and only a few joints of the anal fin-rays 

 remain. The dorsal is situated far back, opposite such traces of the anal as are present ; 

 it aj)pears very small and with very delicate rays, which are also smooth and distantly 

 articulated. The caudal is deeply cleft and inequilobate, the prolongation of the body- 

 axis along the upper lobe being very well developed. 



Observaiions. — When I first saw the above-described specimen I thought I had an 

 example of Bh. Maccotiocliii before me, but a careful examination of it convinced me 

 that it belonged to a distinct and previously unrecognised species. It differs IVom 

 Bh. Macconochii in the following particulars: 



First, in the greater prevalence of a tubercnlated ornament on the external head-bones. 



