TRILOBITES IN VICTORIA MEMORIAL MUSEUM 
37 
pygidium may belong to a species of “ Cheirurus” perhaps to 
C. apollo , and this prediction seems to be verified by a couple 
of specimens collected at Point Levis in 1899 by the late T. C. 
Weston. One of these specimens is a cranidium of P. apollo 
with 12 thoracic segments, and the other is a large pygidium of 
Amphion caleyi. The anterior portion of the pygidium is so 
exactly similar to the thoracic segments of the Pseudosptuzrex - 
ochus as to leave no doubt that the two belong to the same 
species, though not to the same specimen. 
Description. 
Animal elongate oval, spinose, with prominent axial lobes. 
Cephalon semi-circular, dominated by the glabella, which is 
large and prominent, while the cheeks are small and depressed. 
Eyes small, well forward, opposite the second pair of glabellar 
furrows. No spines at the genal angles. The facial suture cuts 
the anterior margin close to the glabella, and back of the eye 
runs outward and a little backward, so that it cuts the margin 
again close to, but in front of, the genal angle. Free cheeks 
not seen. Fixed cheeks covered with large pits. Glabella 
raised high above the rest of the cephalon, but depressed on 
top. It tapers rapidly towards the front and is marked by three 
pairs of deep, narrow furrows, all of which turn a little back- 
ward at the inner ends. The surface of the glabella is granulose. 
The thorax of this specimen has 12 segments, and it is doubt- 
ful if any are missing. The axial lobe is convex and narrow, 
standing high above the pleural lobes, which are flat, and divided 
by a deep, narrow groove into an anterior and posterior ridge, 
the hinder ridge being extended at the point of geniculation 
into a long sharp spine which turns upward and backward. At 
the geniculation, the pleura are bent abruptly downward, and 
end in blunt spines. 
The pygidium is strongly spinose and is made of four 
segments, the first two of which are hardly different in form 
from those of the thorax. The third and fourth segments have 
the anterior ridge reduced in size, and the posterior ridge flat- 
tened. Between the posterior ridges of the last segment is a 
cuneiform plate which probably represents the original pygidium. 
24853 — 3 
