260 SELACHII. 
one-third the natural size, in PI. YIII. fig. 1, and already 
briefly noticed by E. C. H. Day, loc. cit. The parts are 
much disturbed, and the thick covering of shagreen 
obscures the internal skeleton ; but there is the appearance 
of a blunt rounded snout, and the position of the right 
orbit (orb.) is distinguishable. A few teeth are seen 
bordering the lower margin of the right pterygo-quadrate 
cartilage, and these are of the ordinary type characterizing 
the species. The left pterygo-quadrate (]?tq.) is displaced 
upwards. The shagreen-granules (PI. YIII. figs. 2-5) are 
conical in shape, with ridges and deep furrows diverging 
from the apex, and with a well-defined base; being, indeed, 
very suggestive of the small Carboniferous fossils named 
Petrodus. These granules are largest upon the top of the 
head (figs. 2, 3), and are especially conspicuous between, 
and immediately in advance of, the orbits ; they are much 
smaller behind the head, and tend towards fusion into 
small groups of three (figs. 4, 5). Their relative propor¬ 
tions are shown by the figures, which are all drawn of 
three times the natural size. Behind the orbit on the 
right side, and on the same level as this aperture, are fixed 
two large recurved semi-barbed spines, upon triradiate 
bases (fig. 1 c.s. 1 , c.s. 2 ), which have already been recognized 
by Charles worth and Day as identical with the supposed 
teeth described by Agassiz under the name of 8'phenon- 
cJius. Though probably slightly displaced, these append¬ 
ages have the appearance of being almost in their natural 
position ; and the corresponding spines are seen upon the 
left side. Each of the anterior pair has two protuber¬ 
ances at the base of the “crown,” while in the posterior 
pair these are absent. Purchased, 1866. 
P. 3159. liemains of a larger fish, comprising cartilage-fragments 
of the head and appendicular skeleton, two broken cephalic 
spines, the imperfect dorsal spines, and shagreen. 
Enniskillen Coll. 
P. 3160. Crushed skull and mandible, side view, showing a portion 
of the displaced dentition and traces of shagreen, associated 
with other fragments of cartilage, and the two dorsal fin- 
spines. Enniskillen Coll. 
P. 3161. Bemains of the left mandibular, pterygo-quadrate, and 
other cartilages, with the scattered dentition and traces of 
shagreen. The specimen has been broken across the middle 
