388 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



Thorax ; 



Length 12.0 



Width at fourth segment t 19.0 



Width of axial lobe at first segment 5.5 



Width of axial lobe at ninth segment 4.0 



Pygid 



mm: 



Length 70 



Width at union with thorax 12.0 



Fragments of this species are quite abundant in the limestones and 

 interbedded shales. A few entire specimens are found in a fine argil- 

 laceous 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 crani- 

 dium in the limestone. 



In general outline and appearance Asaphisciis iddingsi approaches 

 the type of the genus, A. wheeleri Meek (p. 390). 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: (ssr and 36e) 

 Fu-chou series, shales interbedded with limestones near the base of 

 the series just above the white quartzite [see Blackwelder, Research 

 in China, Vol. i, Pt. i, p. 92, for general section giving stratigraphic 

 relations] ; 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. 



ASAPHISCUS ? MINOR, new species 



Plate 61, figs. 3, 2a-b 



Asaphiscus minor Walcott, 1908, Smithsonian Misc. Coll., Vol. 53, p. 178. 

 (Name listed in fauna of Weeks formation.) 



This is a small species with only seven thoracic segments and with 

 rather strong genal spines. It has four rings and a terminal section 

 on the axial lobe of the pygidium and four flat segments on the pleural 

 lobes separated by narrow, shallow furrows. 



Surface of test apparently finely granulated. The average length 

 of the dorsal shield is about 14 mm. One has a length of 17 mm. 

 Asaphiscus ? minor differs from A. f granulatus and A. ? unispinus 

 in having seven thoracic segments and in the absence of a thoracic 



