Vol. I. 



Sun — Cambrian Faunas of North Ghir 



(iv) 77 



This variety differs from type species in the distinctly punctate character of the 

 surface, straighter frontal edge of the glabella, in the narrower anterior lobe and in the 

 free cheeks. 



The general form of the cranidium and the pustulose and distinctly punctate 

 character of the surface suggest Pt. angulata, but it differs greatly in the straightened 

 margin of the frontal border instead of the angular one. 



This variety was obtained from the highest cambrian beds of Chau-^VIi-Tien five 

 meters above the Orthoceras horizon. It is associated with Changia chinensis. 



Measurements : — • 



Horizon and Locality: Uppermost Cambrian: from the upper limestone at 

 Chau-Mi-Tien, Shantung. I tentatively put it in the Fengshan horizon, separating these 

 beds from the Chaumitien limestone. Collected by University Excursion of 1923. (Y. T. 

 Chao, K. M. Wang, C. C. Yang and C. C. Tien Coll.) 



AndersSONIA Sun, subgenus of PtyCHASPIS (Subgenus nov.) 



Cranidium gently convex, the width at the palpebral lobe and the length 

 subequal. Glabella moderately convex, short, usually broad opposite the palpebral lobe 

 by outcurving at the sides of the glabella, the front narrowly rounded. A very distinct 

 backward-curving posterior furrow separates the anterior lobe and the narrow transverse 

 lobe; the anterior lobe laterally extended at the base becoming less so toward the front, 

 marked by one pair of very short and distinct furrows extending obliquely inward and 

 backward; the second lobe slightly narrow in the middle, becoming wide at the sides, 

 separated from the occipital ring by a transverse occipital furrow; occipital ring little 

 wider than the second lobe and of uniform width; dorsal furrows rounded, distinct and 

 subparallel. 



