Page:Walcott Cambrian Geology and Paleontology II.djvu/138

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82
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOL. 57

AGRAULOS SORGE, new species
Plate 15, fig. 1

This species is represented by a single specimen of the central portions of the cephalon. Among the Chinese species referred to Agraulos it may be compared with A. dryas Walcott, from which it is readily distinguished by its broader, less convex glabella and its almost smooth, instead of strongly punctate, surface.

Agraulos sorge appears to have had a strong occipital spine that projected upward and backward from the occipital ring; only the base of the spine is preserved.

Surface slightly roughened by a minute, irregular, shallow pitting.

Formation and locality.—Middle Cambrian: (35n) Fu-chóu series; limestones near the base of the series just above the white quartzite, collected in a low bluff on the shore of Tschang-hsing-tau island, east of Niang-niang-kung, Liau-tung, Manchuria, China.

Collected by Eliot Blackwelder.


Genus LISANIA, new genus

Cranidium subquadrate in outline, exclusive of postero-lateral limbs. Glabella with slightly converging sides, broadly rounded in front and curving gently down to a narrow furrow separating it from the frontal border, without distinctly marked glabellar furrows; occipital furrow distinct; occipital segment strong. Fixed cheeks narrow; palpebral lobe above the eye nearly one-third the length of the cephalon; palpebral ridge usually defined to the edge of the dorsal furrow beside the glabella. Frontal border slightly convex and separated from the fixed cheeks and glabella by a narrow, shallow but distinct furrow.

The associated free cheeks have a strong genal spine, and associated pygidia a strong central axis marked by three or four transverse rings and a terminal section.

Surface smooth or slightly roughened by very fine shallow pits.

Genotype.—Anomocarella bura Walcott[1] (pl. 15, fig. 2).

Observations.—This genus is founded to receive four species that do not appear to fall within any described genus. From Pagodia it differs in having a longer eye lobe, narrower free cheeks, flatter frontal margin. Pagodia occurs with the Upper Cambrian fauna, Lisania with the Middle Cambrian fauna. From Chuangia (pl. 15, figs. 3-6) it differs in its narrower frontal border, narrower fixed


  1. Walcott, 1905, Proc. U. S. Nat. Mus., Vol. 29, p. 56.