40 THE ROYAL SOCIETY OF CANADA 
not in advance of that of the anal. The scales are rhomboidal and 
rhombic, strong, only slightly over-lapping, enamelled, and sculptured 
with faint, oblique ridges in their hinder half. The articulating 
pegs and sockets are well developed. 
The most striking feature in this fish is the very large pectoral 
fin which, so far as the writer is aware, greatly exceeds in proportionate 
size that of any other described Palæoniscid species. The dorsal 
instead of being opposite the space between the pelvic and anal 
fins, as is usual in the genus Elonichthys, is farther back, in line with 
the anal. The pelvic fins are small, in marked contrast with the large 
pectorals and are midway between the pectorals and the anal. 
This specimen, plate IT, figure 1, the type of the species, is 230 mm. 
long, and 98 mm. deep across the trunk at the anterior end of the 
dorsal and anal fins, representing a fish which was probably about 
370 mm. (roughly 263 inches) long, if the restored dotted outline | 
shown in the figure is moderately correct. In the same figure the 
full length of the pelvic, anal and dorsal fins is estimated from the 
strength of the rays where they are broken off (dorsal and anal fins) 
or have become too slender to leave a lasting impression in the rock 
(pelvic fin). The right pectoral fin protrudes below the trunk, in 
the space between the pelvic and left pectoral fins, in a confusion 
of scattered rays mixed with long strips in which the rays have re- 
tained their proper relative positions. The depth of the fish in life 
was probably considerably less than is indicated by the specimen. 
Above the base of the pectoral fin is seen in a general way the 
hinder curve of the opercular apparatus the elements of which, how- 
ever, are not sufficiently defined for determination. The deep groove 
here probably indicates the position of the clavicle and at its lower 
end, directed forward and upward, are indistinct broken outlines 
suggestive of three or four branchiostegal rays. Outer surfaces of 
bone in this part of the specimen are ornamented with a combination 
of minute shallow depressions and short squamous grooves. 
The pectoral fin has the outline of a short, broad paddle and is 
remarkable for its great size. Its base is short and from it spring 
about thirteen stout, smooth rays which bifurcate at a distance of 
20 mm. from the base. The ray-subdivisions, by four further bisec- 
tions at lengthening intervals, increase in number and slenderness 
distally, plate II, figures 2 and 3. Apparently the articulation of 
the rays does not begin until after the first bisection. The first an- 
terior ray is short, the second is longer, and both seem to be simple 
or undivided but articulated distally. 
