Vol. 1. 



Measurements : 



Sun — Cambrian Faunas of North China 



a 



Length of cranidium 25.5 mm. 



Width of cranidium at the palpebral lobe 

 Length of glabella 21.8 mm. 



Antero-posterior dimension of anterior lobe 12.5 mm. 

 Width of glabella 14.2 mm. 



AVidth of the second lobe (antero-posterior) 4.8 mm. 

 Width of the third lobe ,, ,, 4.0 mm. 



Width of occipital ring ,, ,, 



Length of palpebral lobe 



Horizon and Locality: — Late Upper Cambrian: from 

 limestone and crystalline limestone of Kaolishan formation of Tai- 

 C. Sun Coll.): also the upper Cambrian of Luan-Hsien, Chihh (J. G 



b 

 19.0 mm. 

 17.0 mm. 

 1(>. mm. 

 10.0 mm. 

 10.5 mm. 



3.5 mm. 



3.0 mm. 



3.0 mm. 



12.2 mm. 

 9.0 mm. 

 5.0 mm. 

 6.2 mm. 

 2.0 mm. 

 L5 mm. 



3.0 mm. 



(iv) 75 



d 

 6.0 mm. 

 7.0 mm. 

 5.0 mm. 

 3.0 mm. 

 3.5 mm. 

 1.3 mm. 

 1.0 mm. 

 1.0 tr.m. 

 2.0 mm. 



the conglomerate 

 ■An, Shantung. (Y. 

 , Andersson Coll.) . 



PtVCHASPIS SUNI Grabau (mss.) (sp. nov.) 

 Plate V, Figa. 4a, b. 



1923 Ptychaspis suni (Grabau) Sun, Bulletin of the Geological Society of China, Vol. II, No. 1-2 p. 98. 

 "Only the cephalon exclusive of the free cheeks is known but one free cheek, 

 probably of this species is associated with this. Glabella with parallel sides, moderately 

 convex, the greatest convexity apparently in the anterior lobe, though this is worn. 

 Anterior and second lobe separated by a very faint furrow which is transverse; the width 

 (longitudinal) of the two lobes combined being equal to the width of the glabella which 

 in the specimens described is 5.75 mm. The second furrow is more pronounced, and more 

 concave forward, the third or occipital furrow is strong and transverse. Length of 

 entire glabella, 9 mm; width of occipital ring 1.7 mm. 



' 'Fixed cheeks half the width of the glabella, subsemicircular in outline, with a 

 pronounced narrow palpebral lobe defined by a well-marked furrow. 



"Entire surface of cranidium strongly pustulose except where worn. 



' 'The associated free cheek has about the width of this fixed cheek at the center 

 of the occular lobe. Behind this it curves outward at first obliquely then abruptly 

 ending in a narrow gently tapering genal spine of subcircular section and forming nearly 

 half the length of the cheek. Anterior portion terminating in an angle of about 45°. 

 Outer edge of free cheek gently but regularly curving from anterior end to the tip of the 

 genal spine. 



