NO. 4 CAMBRIAN FAUNAS OF CHINA 99 



The casts of the outer surface indicate that it was smooth or 

 minutely granulose. 



Observations. — This species appears to be quite distinct from any 

 that has been described. The quadrangular glabella with nearly 

 parallel sides distinguishes it from Bathyuriscus hozvclli Walcott and 

 B. productus (Hall and Whitfield). 



Formation and locality. — Middle Cambrian: (36g) (36h) and 

 (350) Fu-chou series ; shales about 130 feet (40 m.) above the white 

 quartzite 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 IDDINGSI, new species 



Plate 16, fig. 3 



Dorsal shield longitudinally oval in outline, moderately convex. 

 Cephalon semicircular in outline ; a little more than one-third of the 

 entire length of the dorsal shield ; bordered by a nearly flat or 

 slightly rounded margin that passes at the genal angle into a moder- 

 ately strong genal spine ; within the genal spine a rounded posterior 

 border is separated from the fixed cheek by a rounded, clearly defined 

 furrow ; the interborder furrow is shallow and rounded. Cranidium 

 moderately convex and roughly subquadrate in outline ; the frontal 

 limb is slightly convex and, with the anterior portion of the glabella 

 and the front margin, forms a gentle slope that is broken only by 

 the slight dorsal furrow in front of the glabella and the shallow 

 intermarginal furrow ; the frontal limb merges on the sides into the 

 fixed cheeks which are a little less than one-half the width of the 

 glabella; posteriorly the fixed cheeks merge into relatively small 

 postero-lateral limbs ; palpebral lobe narrow and extended in front 

 as a low ridge that crosses the fixed cheek to the dorsal furrow near 

 the antero-lateral angle of the glabella ; that portion of the palpebral 

 lobe above the eye is about one-fourth the length of the cephalon. 



Glabella large, slightly narrower in front than at the occipital 

 furrow ; sides nearly straight and slightly converging, frontal margin 

 broadly rounded ; surface marked by very faint impressions of three 

 pairs of glabellar furrows, which can only be seen where the surface 

 is very perfectly preserved. Occipital ring about as wide as the 

 frontal margin and separated from the glabella by a shallow furrow 

 that terminates on the side slightly in advance of the posterior inter- 

 marginal furrow. Free cheeks about as wide opposite the eye as the 

 fixed cheeks ; eye lobe about one-fourth the length of the cephalon. 

 Postero-lateral angle continued backward into a moderatelv strong 



