Page:Second Geological Survey of Pennsylvania Report of Progress PPP.djvu/20



''Ceratiocaris? punctatus'',. Sixteenth Rep. N. Y. State Cab. Nat. Hist., p. 74. 1863.

Ceratiocaris armatus,. Sixteenth Rep. N. Y. State Cab. Nat. Hist., p. 72. 1863.

Ceratiocaris armatus,. Illustrations of Devonian Fossils. Explanation of Pl. 23, Figs. 4, 5. 1876.

Ceratiocaris (Aristozoe,) punctatus,. Illustrations of Devonian Fossils. Expl. Plate 23, Fig. 7. 1876.

Echinocaris punctatus,. Am. Jour. Sci., 3d Ser., Vol. XIX, p. 7. 1880.

obliquely subovate in outline; widest just posterior to the middle, width about two-thirds of the greatest length, which is four-fifths of the free segments of the abdomen; compressed on the anterior half, becoming regularly convex over the posterior portion.

Dorsal line straight, about equal to the width of the valves, situated anteriorly, so that one-third the length of the valves projects beyond the posterior extremity of the hinge.

Margins distinctly marked by a thickening of the test, rounded in front, making a broad curve along the lower edge of the valve, more rapidly curving around the lower posterior portion, and extending in nearly a straight line to the extremity of the dorsal line.

The cephalic portion of the carapace is distinctly marked by a furrow beginning at a point a little anterior to the middle of the dorsal line, curving outward and extending to a point on the lower anterior margin of the valve. This area, therefore, occupies the upper anterior portion of each valve, and is of a broad triangular form with curved sides. It is ornamented by a large rounded elevation, narrow