250 PALEOZOIC PALEONTOLOGY. 
PROETUS? SPINOSA N.. sp. 
Plate XXII., Fig. 26. 
Description.—Pygidium semi-circular in outline, rather strongly 
convex, with a very slight, blunt point posteriorly. Axis with eight 
well-defined segments; occupying about one-third of the entire width 
of the pygidium anteriorly, tapering regularly to the posterior ex- 
tremity, which is bluntly rounded and lies within the marginal border. 
Plurz convex, marked by six well-defined, grooved segments, curving 
rather abruptly to the margin, with a concave furrow within the 
narrow marginal border. 
The dimensions of the best-preserved specimen are: length, 10 mm. : 
width, 13 mm. 
Remarks.—This trilobite is represented only by several pygidia. 
most of which are but fragmentary. It apparently belongs to some 
species of Proetus or, perhaps, Phacops, but the material is not suffi- 
cient for certain generic identification. 
CALYMENE CAMERATA Con. 
Plate XXII., Figs. 22-25. 
1842. Calymene camerata Con., Jour. Acad. Nat. Sci. Phil., vol- 
VED. 278. 
1852. Calymene camerata Hall, Pal. N.-Y., vol. IL, p. 337, pl. 78, 
figs. 10 a-f. 
Description.—Head semi-circular in outline, the marginal border 
elevated in front. Glabella prominent, truncate in front, broadest 
through the posterior pair of lateral lobes; the dorsal furrow narrow 
and deeply impressed. The first pair of lateral furrows and lobes 
very faint, scarcely recognizable in some specimens; the second pair 
of lateral furrows deeply impressed, directed obliquely backward, their 
length a little less than one-fourth the width of the glabella, con- 
nected posteriorly by a slight depression with the third furrows; 
second lateral lobes convex, subelliptical in outline, connected across 
the dorsal furrow with the fixed cheeks; third pair of lateral fur- 
