(iv) 62 Palxont<hO(,ia Sinica ' Ser. B. 



Granidium subrectangular in outline, exclusive of postero-lateral limb. Glabella 

 moderately convex, sub-cylindrical with both sides parallel, slightly rounded in the front. 

 It is marked by three pairs of glabellar furrows ; the posterior pair shallow, distinct, 

 extending obliquely inward and backward and connecting in the middle; the second pair 

 short and shallow, being parallel to the posterior pair; the first or anterior pair very 

 short about one fifth the width of the glabella; a median longitudinal ridge very pro- 

 nounced, extending from the frontal furrow to the occipital furrow. Occipital furrow 

 broad and rounded, slightly narrow in the center; dorsal furroAV broad deep and rounded; 

 frontal groove or furrow rounded and distinct; occipital ring transverse and of nearly 

 uniform Avidth. 



Fixed cheeks very narrow, about one fourth the width of the glabella at the 

 palpebral lobe; palpebral lobe very small and situated opposite the second furrow of the 

 glabella and a little in front of the center of the glabella. The facial suture curve slightly 

 outward from Ihe frontal margin, thence curves inward to the anterior angle of the palpe- 

 bral lobe and around it, and finally extends obliquely outward to outline the free cheeks 

 from the postero-lateral limbs. 



Frontal border slightly convex or flat with antero-lateral angle rounded, very 

 broad, of uniform width throughout, about one fourth the length of the cranidium, the 

 middle part of the border very slightly impressed. 



An associated free cheek probably of this species, is large and broad with flat 

 broad border and ending in a strong genal spine. 



Surface strongly punctate. 



This genus is entirely distinct from any other known in the Upper Cambrian of 

 China and evidently belongs to the family Dikelocephalinse.. Q^iadraticephalus differs from 

 Saukia in the longer subrectangular glabella with subparallel sides and straight frontal 

 margin, small eye lobe and the punctate character of the surface. 



\ Quadraticephalus differs from Dikelocephalus in the position of the palpebral lobe 

 situated in the front of the middle of the glabella, longer glabella and also in the glabellar 

 furrows. Other differences may be found in future when more complete specimens are 

 obtained. 



This genus is similar to the genus Chuangia in form, but the presence of the 

 median longitudinal ridge, subrectangular glabella with subparallel sides and punctate 

 character of the surface serves to distinquish it from that genus which is found in the 

 Chau-Mi-Tien region of Shantung. The subrectangular glabella, pronounced median longi- 

 tudinal ridge, small eye lobe opposite the second pair of furrows, narrow fixed cheeks and 

 the punctate character of its surface are characteristics of this genus. 



