Uv) 68 



Palxoiitologia Sinicn 



Ser. B- 



semicircular. It is probable that the longest belonged to the long variety and the shorter 

 ones to the short variety. In all other characteristics they do not differ in any way. The 

 axis is salient, truncato-conical, it is formed by seven segments; the terminals are obso- 

 lete. The lateral lobes have six fm-rowed segments, separated from the edge by an 

 oblique and flattened lim.b. " 



Mansuy compared this species with P. campe Walcott from the Upper Cambrian 

 of Chau-Mi-Tien of Shantung; and he also mentioned that this species differs from Wal- 

 cott' s species in the angular anterior edge of the frontal rim and also in the small eye 

 lobe. 



Two varieties were described by him. The width of the glabella equals 8-1 

 hundredths of the length in one variety, while in the other variety the width does not 

 represent more than 60 hundredths of the length. He also mentioned that the short 

 glabella is higher and more incurved longitudinally than the long glabella. 

 In the Kaolishan material four cranidia are represented. 



This new variety differs from the type species in the anterior lobe enlarging forward 

 in the presence of very broad rounded frontal groove separating the frontal rim from the 

 glabella, and in the distinctly punctate character of the surface. 



This variety is rather similar to Ptychaspis acamus var. punctata both in the form 

 of the glabella and the surface character, but it differs from the latter greatly in the 

 angular edge of the frontal rim which has a veiy obtuse angle. 

 Measurements : — 



Length of cranidium 

 Length of glabella 

 Frontal width of glabella 

 Width of anterior lobe 

 Width of second lobe 



Width of frontal rim and groove combined 

 Anterior angle of frontal rim 

 HoRizox AND Lopality: — Late Upper Cambrian: from the uppermost part of the 

 Kaoli formation in the conglomerate limestone of Tai-An, Shantung. (Y. C. Sun Coll.) 



Ptychaspis walcotti Mansuy 

 Plate V, Figs. 2 a. 



1915 Ptychaspis Walcotti Mansuy. Faunes Cambriennes du Haut-Tonkin, p. 22, pi. 11, fig. 1 6a, b, 

 pi. Ill, fig. 1 a-z. Mem. du Serv- Geol. de L'Indochine. Vol- IV, fasc. II. 



