Vol I. Sun — Cambrian Faunas of North China Civ) 61 



triangular in outline ; marked by a broad postero-lateral furrow extending outward but 

 sligbtly backward to both extremities. 



Free cheeks very large, subtriangular in outline, exclusive of genal spine, with 

 a narrow depressed flat border; cheek-body slightly convex and broad, ending in a long 

 genal spine. 



Pygidium transverse, large and with a stiong central axis that terminates wnthin 

 a broad flattened border. It is marked by clearly defined transverse rings that extend 

 out in the pleural lobes to the border. 

 Surface smooth. 



This species is characterized by the elongate cylindrical glabella, broad frontal 

 border and also small palpebral lobe centrally placed. It is represented by several crani- 

 dia, free cheeks and pygidia. 



Horizon and Locality: — Upper Cambrian: Upper zone of the Upper Cambrian 

 of Chau-Mi-Tien region. Shantung. Collected by university expedition. 

 Measurements : — 

 Cephalon 



Cranidium (a-c) 



Length of cranidium 



Front width of cranidium 



Length of glabella 



Width of glabella opposite the palpebral 



lobe 

 Width of frontal border 

 Width of occipital ring 

 Free cheeks (d-f) 

 Length of cheek 

 Width of cheek 



Length of genal spine (preserved) 

 Pygidium (g) 

 Length 

 Width 



Genus QuADRATICEPHALUS Sun (gen. nov.) 

 General form elongate oval; moderately convex. Cephalon transversely semi- 

 ovate with genal angles extended backward in a strong spine. 



