(iv) 78 Palxontologia Sinica Ser. B. 



Fixed cheeks very narrow, about one half the width of the glabella, slightly- 

 convex; the facial suture first cuts the posterior border and then bends inward to the 

 base of the palpebral lobe, curving around it and finally extending outAvard and forward, 

 and then inward again to cut the frontal border; frontal limb narrow slightly convex 

 separated from the narrow elevated frontal rim by a very narrow distinct transverse 

 furrow, frontal rim very narrow, extended transversely with a uniform width throughout. 

 Palpebral lobe large and loiig extending from the very faint anterior furrow of the 

 anterior lobe nearly to the occipital furrow, and separated from the fixed cheeks by 

 an incurving furrow. 



Associated free cheeks large with slender genal spine. 



An associated segment of the thorax, probably of this subgenus is known. Axial 

 lol>e and pleural lobe subequal in length; axial lobe convex; pleural lobes of nearly 

 uniform width throughout except the pleural end. 



An associated pygidium transverse, with the narrow conical axis and flattened 

 margins. 



This new subgenus is included in the subfamily Dikelocephalin^: and is 

 characterized by its slight, convex frontal limb, large and elongate palpebral lobes, 

 narrow fixed cheeks and the narrow elevated frontal rim. 



The narrow frontal limb, elongate palpebral lobe and the form of the glabella 

 suggest the genus Conohefhalina, but the strong lateral furrows, absence of the palpebral 

 ridge and the broad form serve to distinquish it. 



It differs also from Ptiichaspl<i in the prej:;ence of the frontal limb and in the form 

 of the glabella Avhich is broad in the middle. 



This new subgenus is named in honor of Dr. J. G. Andersson, who collected 

 these specimens. 



Ptychaspis (Anderssonia) fengtienensis Sun (subgen. and sp. nov.) 



Plate V, Fig. 7a-c 



This species is represented by three fragmentary cranidia, and separated free 

 cheeks, segment of thorax; and pygidia associated with it. 



The subgeneric description of Anderssonia is based on this species and the 

 specific name is derived from FOngtien where it was found. 



