Page:Walcott Cambrian Geology and Paleontology II.djvu/139

NO. 4 cheeks, and quite unlike associated pygidium. The three genera, Lisania, Pagodia, and Chuangia, all have a strong, nearly smooth glahella and a narrow frontal margin and do not appear to come within the limits of Agraulos, Anomocare, Ptychoparia, Coosia, or Solenopleura.

The species referred to the genus are all small and unfortunately only represented by cranidia and associated free cheeks and pygidia. It may be that when entire specimens of the dorsal shield are found other marked differences will appear between the three genera, Lisania, Pagodia, and Chuangia.

The generic name is taken from Li San, the Chinese assistant of both Dr. Bailey Willis and Dr. Joseph P. Iddings.

The species referred to the genus Lisania are:

L. agonius (Walcott), Kiu-lung group, Middle Cambrian.

L. ajax (Walcott), Kiu-lung group, Middle Cambrian.

L. alala (Walcott), Ch'ang-hia limestone, Middle Cambrian.

L. ? belenus (Walcott), Ch'ang-hia limestone, Middle Cambrian.

L. bura (Walcott), Ch'ang-hia limestone, Middle Cambrian.

''L. cf. bura'' (Walcott), Ch'ang-hia limestone, Middle Cambrian.

Only one specimen of the cranidium of this species is known. In form it is nearest to Solenopleura beroe Walcott. It differs in having a proportionately narrower glabella, more convex free cheeks, more rounded frontal rim, and in the presence of a depression dividing the frontal limb on the median line of the glabella. Its tuberculated surface is much like that of S. beroe.

Formation and locality.—Middle Cambrian: (35r) Fu-chóu series; limestones near the base 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 J. P. Iddings and Li San.

This genus is proposed for a group of Upper Cambrian trilobites in which the cephalon has a truncato-conical or subquadrangular glabella; a narrow, concave frontal limb; and, so far as known, a smooth test.