Page:Walcott Cambrian Geology and Paleontology II.djvu/140

84 The associated pygidium is large, with a strong axis, broad pleural lobes, and few indications of segments.

The general form of the glabella is much like that of some species of Anomocare (pl. 17) but the frontal limb is quite different. The latter suggests Pagodia lotos Walcott but the frontal limb of the latter is absorbed by the rounded frontal rim. In Chuangia the frontal limb and rim meet to form an angle and the rim does not rise above the upward sloping surface of the frontal limb.

Genotype.—Chuangia batia Walcott (pl. 15, figs. 3, 3a). Three other species are known from the Upper Cambrian formations of China: Chuangia nitida, C. nais, and C. fragmenta.

Only a fragment of the cephalon of this species is known. This suggests the glabella of Chuangia batia, but the narrow fixed cheeks serve to distinguish it. The surface is smooth to the unaided eye, and slightly pitted or punctate under a strong lens. The fragment of the cephalon has a length of 16 mm.

Formation and locality.—Upper Cambrian: (C61) a dense black limestone in the uppermost limestone member of the Kiu-lung group, 3 miles (4.8 km.) southwest of Yen-chuang, Sin-t'ai District, Shan-tung, China.

Collected by Li San.

This is a large species that is represented by a part of the central portions of the cephalon. Glabella subquadrangular, moderately convex, narrowing slightly toward its broadly rounded front; without glabellar furrows so far as can be determined; occipital furrow shallow, rather broad, and nearly transverse; occipital ring gently convex, arid slightly wider toward the center; dorsal furrow shallow and clearly defined.

Fixed cheeks about two-thirds the width of the glabella, nearly flat between the glabella and the palpebral lobes, and sloping downward in front to the frontal rim, and back to the posterior furrow;