(iv) 42 Palxontologia Sinica Ser. B. 



to the palpebral lobe, curves around this lobe and finally cuts the fixed cheeks in an 

 outward direction. Postero-lateral limb large and marked by a broad postero-lateral 

 furrow. 



This species is characterized by its small form, short very broad subconical gla- 

 bella, convex frontal limb, and the comparatively narrow fixed cheeks. 



Measurements: — Ha 11 b 



Length of cranidium 1.7 2.0 



Greatest width of cranidium 2.8 3.2 



Horizon and Locality : — Late Lower Cambrian : from Manto shale of Lei- 

 Chuang, 'g^ ^ Luan-Chou; collected by Dr. F. F. Mathieu. 



Ptychoparia yohi Sun (sp. nov.) 



Plate II, Fig. 12. 



This species is represented only by one crushed cranidium slightly broader than 

 long. 



Glabella moderately convex, subconical in outline, the front part regularly 

 round; posterior width broad. It is marked by three pairs of very slightly impressed 

 glabellar furrows. Occipital furrow transverse, shallow and very slightly impressed. 

 Occipital ring very broad at the center and becoming iiarrower at both sides. 



Fixed cheek about the same width of the glabella opposite the palpebral lobe ; 

 palpebral ridge distinct from the anterior part of the palpebral lobe near to the antero- 

 lateral portion of the glabella. The facial suture cuts the frontal border to the anterior 

 part of the palpebral lobe in a convex curve, bends around the latter and finally cuts 

 the free cheeks from the postero-lateral limb, also with a convex curve. 



Frontal limb flat, slightly broader than the frontal rim; frontal rim elevated and 

 with regularly arched outline. 



Surface apparently smooth. 



The general form of the cranidium resembles that of P. fongi Sun, but the diffe- 

 rences between them are mentioned after the description of that species. 



This species is characterized by the smooth conical glabella with a broad base, 

 comparatively broader fixed cheeks, and less distinctly defined occipital and glabellar 

 furrows. This species is named after Mr. S. S. Yoh ^^^ who accompanied me in that 

 region during the University Excursion, 



