NO. 1115. CAMBRIAN FAUNAS OF f'HmA—WALCOTT. 27 



FoTiuiithm and locality. — Middle Cambrian. Shaly limestone in 

 upper portion of Ku San shale, 2.5 miles southwest of Yen Chuang-, 

 Hsin Tai, Shanotung, China. 



Collected by Eliot Blaekwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



Genus OLENOIDES Meek. 

 OLENOIDES (?) CILIX, new species. 



This species is founded on a pygidium that is semicircular in outline, 

 moderately convex, and with a spinose margin. Axis moderately con- 

 vex, conical, with a broadly rounded posterior end. It is divided by 

 three clearly marked, transverse, rounded furrows into a strong ante- 

 rior ring, next to the thorax, two moderately convex i-ings, and a 

 long- terminal portion, which has a slight fourth depression, indicating 

 a fourth ring. The posterior portion of the axis slopes rather rapidl}' 

 down to the margin. Owing to an al)rasion, the presence or absence 

 of the nodes usually present at the end of the axis can not be 

 determined. 



Dorsal furrow rounded and shallow. 



Pleural lol)es flat for a short distance from the axis, and then 

 curve gently downward to the border. They are marked l)y a deep 

 anterior furrow within the narrow, anterior, elevated margin and 

 three furrows that terminate at the margin. The furrows outline 

 three rather broad, slightly convex segments and a posterior area 

 opposite the postero-lateral angle of the axis. The border is practi- 

 cally a continuation of the slope of the segments and furrows of the 

 pleural lol>e. It is marked opposite the segments by live short, 

 backward-pointing, flat, broad spines, and diagonally opposite the 

 lat(n-al angle of the axis by two long, strong, backward-extending 

 spines. In addition, there are two short spines with broad bases back 

 of the axis between the two long spines. 



Outer surface unknown, as the crust has been removed by abrasion 

 or solution. 



The type and only specimen of the pygidium has a length of about 

 12 mm., with a width at the front margin of 19 mm.; the axis has a 

 length of about 9 mm., with a width in front of 6 mm. and at the 

 terminal segment of 3.5 mm. 



This species is characterized b}^ the two long posterior spines and 

 the short - backward-extending lateral spines; the latter spines are 

 essentially of the type occurring on the pygidium of Peltara and Pro- 

 topeltura., but the general character of the pygidium and spines relate 

 it to the group of trilobites here brought together under the genera 

 Do7'yj)yge^ DoTyj>y<jella., DaineseUa, and Olenolde^. 



