(iv) 74 Palseontologia Sinica Ser. B. 



medially and less continuous than in that species. The Fengshan specimens are also 

 uniformly larger. The free cheeks of our species are very distinct. 



''Measurements: The length of the most perfect glabella is 25.5 mm., width of 

 anterior lobe (longitudinal) 12.5 mm., width of central part of glabella 13.5 mm. The 

 diameter of the median portion of the genal spines varies from 3.5 to 4 mm. 



''Horizon and Locality: The specimens occur in a limestone conglomerate of 

 Upper Cambrian collected by Dr. J. G. Andersson at Luan-Hsien, Chihli province. " 

 (Grabau Mss.) 



Five more cranidia of this species were obtained from the Koa^l limestone. Two 

 large ones occur in the same limestone conglomerate and are essentially of the same type 

 as those of the Fengshan limestone. Three other small specimens were found in the 

 crystalline limestone full of Obolus, 2 or 3 meters below. The Shantung specimens 

 are Avell preserved especially in the fixed cheeks, eye lobes and the surface while the 

 Chihli specimens are nearly worn away and difficult for description. 



Fixed cheeks fiat, moderately convex near the palpebral lobe and sloping down 

 the postero-lateral portion ; triangular in outline, exclusive of the palpebral lobe, very 

 broad in the posterior part about the width of the glabella and becoming narrow 

 gradually toward the front; marked posteriorly by a broad and distinct groove, which 

 extends outward from the furrow a little below the occipital furrow to the postero-lateral 

 extremities and broadens slightly outward. It is also marked by distinct raised 

 undulating ridges which are the characteristic feature of this species. 



Palpebral lobe small, elongate, situated just opposite the first glabellar furrow 

 and separated from the fixed cheeks by an incurved furrow and elevated. The occipital 

 ring usually broader than the third lobe, slightly narrow in the center, becoming broad 

 at both sides. It is distinctly marked by a median node. 



The facial sutures cut the antero-lateral portion with a regular convexity to the 

 anterior part of the palpebral lobe; and curving around this lobe, extend outward 

 and backward to the postero-lateral extremities, forming angles of 45° with the posterior 

 margin. 



Surface strongly marked by elevated ridge, and wrinkles and also punctate. 



The concentric wrinkles of the anterior lobe, and the general form of the 

 cranidium suggest P. ceto Walcott from the Upper Cambrian Chaumitien limestone of 

 Chau-jNIi-Tien, Shantung, but our species differs in the longer subglobose form of the 

 anterior lobe of the glabella, the punctate surface with distinct wrinkles and ridges, and 

 also in the greater deflection of the transverse furrow of the glabella. 



