﻿ONYCTI0D0NTID.2E. 393 



attenuated in the distal half, firmly fixed to the supporting hone, 

 and with a relatively small internal cavity ; the teeth diminishing 

 rapidly in size downwards in the series. 



Form, fy Loc. Lower Old Red Sandstone : Herefordshire. 



Fig. 52. 



Onychodus anglicus, A. S. Woodw. — Presymphysial dentition, side view 

 (partly in section), twice nat. size. [Oxford Museum.] 



P. 6252. The inferior portion of a presymphysial bone, exhibited 

 in vertical section in matrix, shown of twice the natural 

 size in PI. XV. fig. 1 ; Bush Pitch, Ledbury. 



Presented by George H. Piper, Esq., 1890. 



The following species are also known only by remains of the 

 presymphysial dentition, of which there are no examples in the 

 Collection : — 



Onychodus arctieus, A. S. "Woodward, Eep. Brit. Assoc. 1889, 

 p. 585, and Geol. Mag. [3] vol. vi. (1889), p. 499.— 

 Lower Devonian ; Spitzbergen. [B-oyal State Museum, 

 Stockholm.] 



Onychodus hopMnsi, J. S. Newberry, Eep. Geol. Surv. Ohio, 

 vol. i. pt. ii. (1873) p. 302, and Palaeoz. Fishes N. America 

 (Mon. U. S. Geol. Surv. no. xvi. 1889), p. 99.— Chemung 

 Group (Upper Devonian) ; Delaware Co., New York. 



Onychodus ortoni, J. S. Newberry, Palseoz. Pishes N. America 

 (Mon. U.S. Geol. Surv. no. xvi. 1889), p. 71, pi. xix. 

 fig. 1. — Huron Shale (Upper Devonian); Franklin Co., 

 Ohio. 



An undetermined species, as large as the type, also seems to be 

 indicated by some robust, sigmoidally curved teeth from the Devo- 

 nian of Gerolstein, Eifel, Germany, preserved in the Museum of 

 Comparative Zoology, Cambridge, Mass., U.S.A. 



