56 
PALEONTOLOGY OF NEW YORK. 
deep; third lateral lobes well-defined, transverse. Occipital furrow narrow, 
becoming wide and deep upon the cheeks; occipital ring very wide upon 
the axial line, but narrowing to the axial furrows and upon the cheeks. 
Cheeks elevated, very convex and protuberant at the sides, constricted at 
their bases by the broad marginal sulcus; posterior slope abrupt. The 
summit about the base of the eye is grooved by a deep orbital sulcus. 
Eyes lunate, elevated, moderately large; palpebrum depressed; lenses 
abundant. 
Thorax and Pygidium unknown. 
Surface covered with conspicuous, often sharp, spiniform tubercles, of 
which the strongest appear to be one in each angle of the occipital ring and 
marginal sulcus, and a single row about the bases of the marginal denticula- 
tions. Upon these processes the ornamentation consists of fine granules. 
Dimensions. The more perfect example of the cephalon has an axial length 
of 45 mm.; a length to the extremity of the cheek spines of 92 mm., and 
a width of 88 mm. 
Observations. All that is known of this remarkable species is from the two 
somewhat fragmentary cephala which were collected in the year 1832. One 
of these is a cast of the dorsal surface and the other preserves nearly the 
whole of the crust. In the peculiar denticulate character of the border, distinct 
from that in the sub-genus Odontocephalus, the species finds an ally in the 
minute Dalmanites pygmceus of the Corniferous limestone. 
Distribution. Upper Helderberg group. Schoharie grit, in the town of Knox, 
Albany county. 
Dalmanites (Corycephalus) pygmaeus, n. sp. 
PLATE 51, FIGS. 5-8. 
Cephalon minute, outline sub-semicircular or sub-elliptical. Surface convex, 
abruptly depressed at the sides. Margin narrow, thickened and produced 
at the genal angles into long slender spines which curve inward toward the 
extremity. 
