C. R. Eastman — On the Genus Feripristis. 391 



by fine vertical markings, and by the impress of the more prominent 

 denticulations upon the outer coronal face of the latter, as seen in 

 Fi^. 1. 



This species occurs in the Chester limestone of Kentucky, at the 

 summit of the Mississippian series ; in the Productive Coal-measures 

 of Ohio and Indiana ; and in the Missourian of Nebraska. 



Feripristis benniei (R. Etheridge, jun,). 



1875. PetalorhyncJms (?) benniei, E,. Etheridge, jun. : Geol. Mag. [2], vol. ii 

 (1875), p. 243, pi. vii, figs. 3, 4. 



1888. Pristodus benniei, R. H. Traquaii' : ibid. [3], vol. v, p. 101. 



1889. Pristodus benniei, A. S. Woodward : Cat. Foss. Fishes Brit. Mus., pt. i, p. 64. 



This species differs from P. semicirciiJaris and F. falcatus in that 

 the coronal margin of the upper tooth is not dentated, but acuminate 

 and smooth, and with delicate punctations like the margin of the 

 lower tooth, the latter being as in F. falcatus. It is stated by 

 Smith Woodwai-d that all the known teeth of this species, which 

 occur typically in the Lower Carboniferous Limestone of Scotland 

 and Derbyshire, are small in comparison' with those of the Yorkshire 

 species, and some doubt is expressed as to whether the non-dentated 

 character of the margin of the upper tooth should not be considered 

 as of generic value. The same author doubtfully assigns one upper 

 tooth in the British Museum to this species, obtained from Richmond, 

 Yorkshire, which appears to differ from the typical teeth only 

 in size. 



A second tooth from the same locality as the last, and apparently 

 referable to this species, is preserved in the Enniskillen Collection 

 belonging to the Museum of Compai-ative Zoology at Cambridge, 

 and is shown of the natural size in Fig. 2. It is quite well 

 preserved, exhibiting the character of the cutting margin with 

 perfect clearness, and showing also several folds on the horizontal 

 portion of the crown. It exceeds the specimen figured by Etheridge 

 in size, and approaches that of F. falcatus. As the upper tooth of 

 F. concinnns (Davis) has not yet been definitely recognized as such, 

 there are no means of determining whether its coronal margin was 

 serrated, as in F. semicircularis and F. falcatus, or smooth and 

 acuminate, as in the species under discussion. In the latter event 

 it would probably be difficult to distinguish between the upper teeth 

 of F. concinnns and F. benniei, unless size alone were a criterion. 

 The slight extent to which the coronal apex is produced in the 

 present specimen, however, does not warrant its association with 

 P. concinnns in the present state of our knowledge. Hence it may 

 be aflSrmed that P. benniei accompanies the two other British species 

 of Feripristis at the Richmond locality. 



