{waireaves} FOSSIL FISHES OF THE DEVONIAN ROCKS 251 
row, much less extensive, placed just below the tip of that fin.” The 
oral region and the eye plates of B. Canadensis are described in minute 
detail and illustrated in this paper. In Professor Patten’s figure of 
the ventral side of the head of this species, the two plates which Smith 
Woodward and Traquair call the maxillary plates, are regarded as the 
mandibles, and the maxillæ are described by Patten as “ peculiar 
S-shaped plates lying behind, or more frequently underneath, or dorsal 
to, the mandibles.” 
Finally, in Part II, No. 2, of his Fishes of the Old Red Sandstone, 
published by the Palæontographical Society in 1904, Dr. Traquair gives 
a new and detailed description of the genus Bothriolepis, with two 
restored figures, the one of the dorsal, the other of the ventral surface 
of B. Canadensis, both of which are here reproduced on Plate 1. 
SUB-CLASS III. ARTHRODIRA. 
(7) Coccostrus CANADENSIS, Woodward. 
Coccos’eus Canadensis, A. Smith Woodward. 1892. Geol. Mag., dec. 3, vol. ix, 
p. 483, pl. 13, fig. 2. 
The type and only known specimen of this species was collected 
by Mr. Jex in 1891, and is now in the Geological Department of the 
British Museum (Nat. Hist.). It is thus described by Dr. Woodward, 
omitting some references to the original figure, which is not reproduced 
in this paper. 
“This species as yet is not satisfactorily definable, being known 
only by a weathered beach-pebble exhibiting an impression of the head- 
shield. The features shown, however, suffice to readily distinguish 
this shield from all described forms except the typical Coccosteus dect- 
piens; and from the head shield of the latter it evidently differs, (1) in 
its greater length as compared with the breadth, (2) in the narrower 
median occipital, and (3) in the relatively smaller size of the central 
plates. 
“Almost the whole of the border of the shield is destroyed, but 
most of the sutures and the sensory canals are distinctly exhibited in 
impression. The median occipital plate is considerably more than 
twice as broad behind as in front, and its superficial tuberculations are 
arranged in radiating series towards the posterior border. The lateral 
occipital, marginal, preorbital, postorbital, and pineal plates are imper- 
fect and do not require special note; while the central plates form a 
relatively small and not quite symmetrical pair. The sensory canals of 
each side are distinctly united in the usual manner by a transverse 
commissure across the central plates.” 
