260 
HKLACHll. 
one-third the natural size, in PI. Vlll. 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 t hose are of the ordinary type characterizing 
the species. The left pterygo-quadrate (ptg.) is displaced 
upwards. The shagreen -granules (PI. Vlll. 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 
Fetrodm. These granules are largest upon the top of the 
head (figs. 2, 3), and are espcciiiUy 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. Pohind the orbit on the 
right side, and on the same level as this aperture, arc fixed 
two largo rocurved semi-barbed spines, upon triradiate 
bases (fig. 1 c.s.‘, c.s.*), which have already been recognized 
by Charlesworth and Day as identical with the supposed 
teeth described by Agassiz under the name of Sphoion- 
chus. Though probably slightly displaced, these append- 
ages have the ii 2 >pearance of being almost in their natural 
Ijosition ; and the corresponding spines arc scon uj)ou the 
left side. Each of the anterior jiair has two protuber- 
ances at the base of the “crown,” while in the posterior 
pair these are absent. Purchased, 1866. 
P. 3159. llemains of a larger fish, comxnising cartilage-fragments 
of the head and aj)pendicular skeleton, two broken cephalic 
spines, the imperfect dorsal sjunes, and shagreen. 
Enniskillen Coll. 
P. 3160. Crushed skull and mandible, side view, showing a portion 
of the disidaced dentition and traces of shagreen, associated 
with other fragments of cartilage, and the two dorsal fin- 
spines. Enniskillen Coll. 
P. 3161. llemains ol the left mandibular, ^Aerygo-quadratc, and 
other cartilages, with the scattered dentition and traces of 
shagreen. The specimen has been broken across the middle 
