Vol. 1. 



Sun — Camhrian Faunas of North China 



(iv) 27 



width; dorsal furrow shallow and distinct; frontal groove shallow and distinct connecting 

 the frontal rim and the glabella. 



Glabella cylindrical, about one-third the width of the cephalon, contracted at the 

 middle by slight incurving of the sides. It is divided by two slightly impressed backwards 

 curving furrow into three lobes. The second lobe is distinctly marked by an elongated 

 tubercle ; frontal groove shallow and distinct ; two small triangular lobes at the postero- 

 lateral margin of the glabella. 



Thorax unknown. 



Caudal shield moderately convex, little wider than long, with uniformly elevated 

 rim. Axial lobe short, about one third the total length, pentagonal in outline bounded 

 laterally by two strong oblique furrows and posteriorly by two slightly impressed curving 

 furrows which meet at an obtuse reentrant angle. A large, distinct and elongated tubercle 

 is situated at the middle of the margin of the axial lobe. Limli moderately convex, marked 

 by a median groove from the median tubercle of the axis near to the posterior margin. 

 On either side of the median tubercle and the caudal groove is a row of nine foramina in 

 the form of an elongated elliptical ring. This feature is beautifully shown. 



This species is very closely related to Agnostus cyclopyge Tullberg of Europe. The 

 cephalic groove of the head, short pentagonal shaped axial lobe suggest A. cyclopyge; 

 Ijut it differs in the absence of the distinct lateral spines and the presence of the elliptical 

 ring of foramina of the pygidium. 



This is the first species of Agnostus found in the Upper Cambrian of China, and it 

 is significant that it is very closely related to A. cyclopyge Tullberg, an index fossil of the 

 Upper Cambrian of Europe. 



