﻿3C2 CROSSOPTERYGII. 



culated ; teeth compressed, with a sharp anterior and posterior 

 edge. Ossified ring-shaped vertebras in the abdominal region. 

 Infraclavicle without an ascending process. Anterior dorsal fin 

 opposed to the pelvic pair, and the posterior dorsal to the anal ; 

 tail diphycercal or slightly heterocercal, the caudal fin large and 

 triangular, abruptly truncated or excavated posteriorly, the upper 

 lobe nearly or quite as large as the lower, and the rays at the 

 extremity of the caudal body-prolongation extending somewhat 

 further backwards than the others. 



Eusthenopteron foordi, Whiteaves. 



1881. Eusthenopteron foordi, J. F. Whiteaves, Canadian Naturalist, n. s. 



vol. x. p. 31, woodc. 

 1889. Eusthenopteron foordi, J. F. Whiteaves, Trans. Roy. Soc. Canada, 



vol. vi. sect. iv. p. 79, pi. v. fig. 5, pis. vi., vii., and woodc. fig. 1. 



1889. Phaneropleuron curtum, J. F. Whiteaves {errore), ibid. p. 91, 

 pi. x. fig. 1. 



1890. Eusthenopteron foordii, R. H. Traquair, Geol. Mag. [3] vol. vh\ 

 p. 17. 



Type. Imperfect fish ; Geological Survey Museum, Ottawa. 



The type species, attaining a maximum length of not less than 

 0-6. Head longer than deep, occupying somewhat more than one 

 sixth of the total length ; the bones ornamented with granulations 

 more or less fused into short tortuous rugse. Pelvic fins much 

 smaller than the pectorals, arising about the middle point of the 

 trunk, directly opposed to an anterior dorsal fin of nearly equal 

 size ; anal and posterior dorsal fins relatively large, very high, 

 narrow, and acuminate, equal and opposite, situated close to the 

 base of the caudal fin ; caudal fin about as long as deep, having the 

 hinder border much excavated above and below the caudal body- 

 prolongation. Scale-ornament very delicate. 



. The fine state of preservation in which this species is discovered 

 renders it possible to determine many points in the structure of the 

 endoskeleton — notably the arrangement of the basal cartilages of 

 the fins, which closely resemble those of Tristichopterus. A distinct 

 ring of sclerotic plates round the eye is also conspicuous in some of 

 the type specimens. 



Form. Sf Loc. Upper Devonian : Scaumenac Bay, P. Q., Canada. 



P. 5219. Fish, 0-25 in length, with imperfectly preserved head, 

 displaying all the fins except the pectorals. 



Presented by A. H. Foord., Esq., 1886. 



