RHADINICHTIIYS ORNATISSIMUS. 127 



the brain iiiul the details of tlij labyrinth of the enr are preserved, even a few blood- 

 vessels being traceable. I may anticipate a little by stating that in a specimen of Rh. 

 carinalas (Ag.) in my possession, one of the semicircular canals and also an otolith are 

 distinctly shown. 



In form and lins Rhadinicht/ii/.'^ has affinities with Ci/dopfi/chins, but the scales are 

 angulated all over the body, none of their corners being rounded off. Also, though on 

 a small scale, this genus recalls the Permian Pijyoplenis, but the anal fin is not 

 produced backwards in a fringe-like manner, as it is in the last-named form. 



It is i)re-eminently a Carboniferous genus, the only exceptions to this position being 

 the Rhadinkhthys clcvoiiicns (Clarke) and R/i. Dcani, Eastman, from the Upper 

 Devonian of New York and Kentucky respectively. 



1. Rhadinichthys ORNATISSIMUS, J(/asdx,, sp, Plate XXVIII. 



PAr-^ONiscus ORNATISSIMUS, Agass'iz. Poiss. Foss., vol. ii, pt. i, 1835, p. 92, pi. 



x a, figs. 6, 8 (_)ion figs, 5, 7). 



liiiADiNiCHTUYS oiiNATissiMus, Traquaiv. Quart. Jouru. Geol. Soc, vol. .xxxiii, 



1877, p. 559. Also Proc. Roy. Soc. 

 Edinb., vol. i.v, 1877, p. -132; Proc. 

 Roy. Soc. Ediub., vol. xvii, 1890, pp. 

 391, 397 ; Distrib. of Fossil Fish- 

 remains in tlio Curb. Rocks of the 

 Edinburgh District (Trans. Roy. 

 Soc. Ediub., vol. xl, pt. iii, No. 28), 

 pp. 690, 691, 692, etc. 



— LEPTURUS, Traquair. Proc. Roy. Soc. Edinb., vol. ix, 1877, 



p. 437. 



— ORNATISSIMUS, A. S. Woodward. Cat. Foss. Fishes Brit. Mus., 



pt. ii, 1891, p. 462. 



Specijic Characters. — Occasionally attaining a length of ten inches. Length of head 

 contained about one-fifth in the total; external liead-bones sharply striated. Scales 

 rather large, those of the flank ornamented with numerous sharp and slightly sigmoidal 

 ridges and furrows, whose direction is mostly parallel with the upper and lower margins, 

 and ending in denticulations of tlie posterior border. Paired fins rather small ; median 

 fins well developed, articulations of the rays rather distant ; fulcra distinct ; body 

 prolongation in upper lobe of caudal fin weak. 



Ristory. — '^PaIcE07iiscus" ornatissimus was described by Agassiz from three speci- 

 mens, all of which are figured in the ' Poissons Fossiles.' Two of these from 

 Burdiehouse are in the collection of the Royal Scottish Museum, Edinburgh ; they are 

 in a very bad state of preservation, though enough is seen of their structure to convince 

 one that they belong to two different species. 'JHie original of fig. 5, tab. 10 « 



