PALEOZOIC PALEONTOLOGY. 
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ARTHROPODA. 
TRILOBITA. 
HOMALONOTUS VANUXEMI Hall. 
Plate XLIV., Figs. 4-7. 
1859. Homalonotus vanuxemi Hall, Pal. N. Y., vol. III., p. 352, pl. 
73, figs. 9-14. 
1888. Homalonotus vanuxemi Hall and Clarke, Pal. N. Y., vol. 
WoT. jp. 11 plo Baise —2. 
Description.—Cranidium subtrigonal in outline, truncated an- 
teriorly. | Glabella depressed-convex, bounded by an _ ill-defined 
dorsal furrow, subquadrangular in outline, narrower in front; lateral 
lobes and furrows obsolete; occipital furrow well-defined, produced 
laterally upon the fixed cheeks; occipital segment rather narrow, flat. 
Anterior margin of the cranidium produced into a rather broad and 
flat border in front of the glabella. Fixed cheeks moderately convex, 
eye-lobes not conspicuous. Free cheeks subtriangular, longer than 
broad, with an ill-defined marginal border. Entire surface of the 
cephalic test, so far as observed, minutely pitted or punctate. 
Pygidium subtriangular in outline, the lateral margins meeting 
at the posterior extremity in an obtusely-rounded angle of less than 
90°, strongly-convex transversely along its anterior margin, sloping 
steeply along its median line from the anterior margin to the pos- 
terior extremity, the slope beyond the extremity of the axis being 
steeper than in front of that point. Axis scarcely defined, occupying 
more than one-third of the width of the pygidium anteriorly, and 
about five-sixths its total length, marked by about twelve segments, 
which become fainter upon the pleural slopes. 
The dimensions of a large pygidium are: length, 70 mm.; width, 
60 mm.; and convexity, 50 mm. This would indicate an individual 
of from 250 mm. to 275 mm. in total length. The dimensions of 
the head of a smaller individual are: length, 20 mm.; width, 40 mm. 
Remarks.—This is one of the common species in the trilobite bed 
at the base of the Oriskany series, but it always occurs in a frag- 
