254 ROYAL SOCIETY OF CANADA 
cited above. In the second part of the British Museum Catalogue of 
Fossil Fishes, the genus is thus defined :— 
“Body much depressed anteriorly, with rounded or ovoid scales, 
of which the exposed portion is ornamented with granulations and 
antero-posteriorly directed ruge. Head bones more or less tubercu- 
lated; teeth compressed, with a sharp anterior and posterior edge. 
Ossified ring-shaped vertebræ 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 backward that the others.” 
In the “Outlines of Vertebrate Paleontology for Students of 
Zoology,” the description of this genus is as follows :— 
“ Eusthenopteron. 
“A fish closely resembling Rhizodopsis, but with. laterally com- 
pressed teeth and nearly diphycercal caudal fin, which is truncated or 
wavy at the hinder border. A pineal foramen occurs between the 
frontal bones. The eye is provided with a ring of sclerotic plates. 
The examples of the typical and only known species, Z. foordi, from the 
Upper Devonian of Canada, are important as displaying the calcified 
supporting cartilages of some of the fins. The pectoral fin has only 
one stout basal cartilage, and is simply Gegenbaur’s “ archipterygium ” 
partly atrophied, with some elements fused together. The bases of the 
second dorsal and anal fins are shown to be almost identical, each hav- 
ing three baseosts supported by the broad end of a single axonost, which 
is directly apposed to a single arch of the axial skeleton. There are 
ealcified ring-vertebre in the abdominal region.” 
(10) EUSTHENOPTERON Foorp1, Whiteaves. 
Eusthenopteron Foordi, Whiteaves. 1881. Canad. Nat. & Quart. Journ. Se. 
vol. 10, no. 1, p. 31, woode.; and Amer. Journ. Sc., vol. 
xxi, p. 495. 
a es Whiteaves. 1889. Trans. Royal Soc. Canada for 1888, 
vol. vi, sect. iv, p. 79, pl. v, fig. 5, pls. vi, vii, and wood- 
Lubes vie IL 
“ Phaneropleuron cur‘um,’ Whiteaves (inadvertently). 1889. Idem, sect. iv, p. 
ORDER ole 
Fir ethenopteron Foordi, Traquair. 1890. Geol. Mag., dec. iii, vol. vii, p. 17. 
of A. Smith Woodward. 1891. Cat. Foss. Fishes Brit. Mus., 
pt. ii, p. 362: and (1898) Outl. Vertebr. Palæont. etc. 
p. 25, fig. 25 (pectoral fin of), and p. 77, fig. 58. 
