Page:Walcott Cambrian Geology and Paleontology II.djvu/157

NO. 4 Observations.—Fragments of this species are quite abundant in the limestones and interbedded shales. A few entire specimens are found in a fine argillaceous shale a short distance above the white quartzite at the base of the section, and it is from the best specimens of these that the above description was drawn, together with specimens of the cranidium in the limestone.

In general outline and appearance Asaphiscus iddingsi approaches the type of the genus, A. wheeleri Meek. Asaphiscus iddingsi has a genal spine, a longer eye lobe, a proportionately shorter cephalon, and nine, instead of eight, segments in the thorax.

Formation and locality.—Middle Cambrian: (35r), (36e) Fu-chóu series; shales interbedded with 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 J. P. Iddings and Li San.