74 
PALEONTOLOGY OF NEW YORK. 
tubercles. There appears to have been also a strong spine near the ocular 
node just outside the lateral lobes. The occipital furrow is broad and 
shallow over the axis, deeper along the abruptly sloping sides of the cheeks; 
the occipital ring is very broad, depressed-convex, with a gentle anterior and 
an abrupt posterior slope, and narrows rapidly towards the axial furrows; 
on its posterior edge it bears a row of from six to eight strong clavate 
tubercles. 
Cheeks separated from the lateral lobes by a faint furrow, which leaves the 
position of the eyes elevated, and gives to the fixed portions of the cheeks 
an abrupt anterior and posterior slope. The free portion, as far as can be 
judged from two fragments, was somewhat constricted or narrowed beyond 
the terminations of the fiicial sutures, and its posterior margin carried a 
series of more or less irregular, tubercled spines. The genal extremities 
were acute and attenuate, and the anterior margin regular. 
The surface of the cephalon is covered with coarse tubercles which are 
largest on the posterior extremity of the anterior lobe, but are almost all 
absent on the median depression behind this lobe, and are obsolete on the 
constricting furrow about its base. 
Thorax. The character of this part of the animal is known only from two 
impressions, one of a segment of a small individual, the other the axial arch 
of the segment of a large example. The segment shows a relatively wide 
and strongly arched axis and narrow pleurae deflected at about the middle of 
their length. The axial arch bears two strong, straight, divergent spines, 
reaching a height equal to the width of the axis, and apparently directed 
posteriorly. 
Pygidium semi-circular in general outline, wider than long; strongly spinose on 
the lateral and posterior margins; anterior margin nearly transverse. 
Axis relatively wide, being about one-third as wide as the shield on 
the anterior margin, and tapering rapidly to an elevated termination at a 
point about half way across the pygidium. It bears two annulations, behind 
which are situated a pair of conspicuous tubercles, and between this point 
