4 DR. A. SMITH WOODWARD ON THE [vol. lxXV^ 



consist mostly of the dense dentine (black in the fossil). In con- 

 tinuation of this series of small teeth on each side over the mandi- 

 bular ramus, there are five teeth closely similar to those of the 

 opposing jaw and nearly as large. The coronal ridge of highly- 

 vascular dentine is especially conspicuous ; and in one of the back 

 teeth on each side, where unworn, it bears a trace of the coarse 

 serration (PI. I, fig. 6) already noted in one of the opposing teeth.. 

 Two of these teeth detached from the matrix are interesting, as 

 showing the shallow but relatively-large root, which is scarcely 

 overhung by the crown in any part. The antero-inferior face of 

 the root (PL I, fig. 5 a) is gently convex and smooth, tapering 

 below where it ends in a series of five short blunt radicles. The- 

 posterior face, also smooth, is nearly vertical and shallow (as shown 

 in cross-section, PL I, fig. 5b). 



Scattered round the jaws on the shale are some remains of coarse- 

 shagreen, the granules being very irregular in size and shape ; but 

 all possess a shining convex outer surface. The granules (figs. 7-9) 

 are usually quadrilateral with rounded angles, sometimes ovoid,, 

 sometimes indented or coarsely crimped round the margin. Most of 

 them are smooth, but some behind the symphysial dentition are- 

 crossed by fine parallel grooves, and a few farther back bear traces. 

 of concentric ridging. Very similar shagreen has already been 

 described in the L^pper Permian Janassa bituminosa, and is well 

 seen in an example of this* species in the British Museum (Natural 

 History), No. 48424. 



With an extensive nomenclature based on isolated teeth of" 

 uncertain relationships, it is difficult to name the specimen now 

 described even generically. As, however, the teeth at the back of' 

 the symphysis are essentially identical with those from the Lower- 

 Carboniferous of Derbyshire referred to the type species of 

 Climaxodus, 1 it is probably best to assign the specimen to this, 

 genus. The only earlier name given to teeth much resembling 

 those in the fossil is Chomatodus' 2 ; but on the original evidence 

 this could never be defined, and the type species. Chomatodus 

 cinctus, is almost certainly a Cochliodont, not a Petaloclont. Later- 

 names for nearly similar teeth are Peltodus* and Tanaodns^ and 

 it is interesting to notice that under the second St. John & Worthen 

 have grouped a series of isolated teeth representing most of the- 

 variations seen in the new fossil. From all the described com- 

 parable teeth the hinder symphysial teeth in this fossil are- 

 distinguished by the peculiar tapering shape of the crown. The 

 specimen therefore represents a new species, which may be appro- 

 priately named CI i maxod u s wisei. 



1 Climaxodus imbricatus, F. McCoy, Joe. jam cit. 



2 L. Agassiz, 'Becherches sur les Poissons Fossiles ' vol. iii (1838) p. 107. 

 See also references in A. S. Woodward, Catal. Foss. Fishes Brit. Mus. pt. i 

 (1889) pp. 218-28. 



3 J. S. Newberry & A. H. Worthen, ' Geol. Surv. Illinois -Palaeontology '' 

 vol. iv (1870) p. 362. 



4 O. St. John & A. H. Worthen, ibid. vol. vi (1875) p. 367. 



