DESCRIPTION OF GENERA AND SPECIES. iyi 



Surface smooth under a strong lens. 



The largest of three specimens of a cephalon has a length of 20 mm., with a 

 width at the palpebral lobes of 26 mm. 



This species is characterized by its large size, concave frontal rim, and nearly 

 smooth glabella. A somewhat similar cephalon occurs in the upper portion of 

 the Ch'au-mi-tien limestone, at about the same horizon, 9 miles (14.4 km.) north 

 of Sin-t'ai-hien. 



Formation and Locality. Upper Cambrian: (0(54) Upper limestone member 

 of the Kiu-lung group [Blackwelder, 19070, pp. 37 and 42 (first list of fossils), and 

 fig. 10 (bed 20), p. 38], 2.7 miles (4.3 km.) southwest of Yen-chuang; (061), a dense 

 black limestone in the uppermost limestone member of the Kiu-lung group [idem, 

 pp. 37 and 41 (third list of fossils), and fig. 10 (bed 13), p. 38], 3 miles (4.8 km.) 

 southwest of Yen-chuang, Shan-tung ; and (0 11) , crystalline limestone 60 feet (18 m.) 

 above the base of the uppermost limestone member [idem, pp. 37 and 41 (last list of 

 fossils)], 2.1 miles (3.4 km.) southwest of Yen-chuang, Sin-t'ai district, Shan-tung; 

 also (033a), talus near the base of the cliff of Ch'au-mi-tien limestone [idem, p. 41 

 (part of last list of fossils)], 9 miles (14. 4 km.) north of Sin-t'ai-hien, Shan-tung, China. 



Collected by Eliot Blackwelder and Li San. 



A form apparently identical was found by Mr. Blackwelder in limestone blocks 

 in talus at (044), 200 feet (60 m.) above the top of the section containing 04G, 048, 

 and 051, at Ch'au-mi-tien, Ch'ang-hia district, Shan-tung, China. 



Chuangia fragmenta Walcott. 

 Plate 16, Figure 2. 



Chuangia fragmenta WALCOTT. 1911, Smithsonian Misc. Coll., vol. 57, No. 4, p. 84, plate 15, fig. 4. 

 (Described and discussed as a new species essentially as below.) 



Only a fragment of the cephalon of this species is known. This suggests the 

 glabella of Chuangia batia, but the narrow fixed cheeks serve to distinguish it. 

 The surface is smooth to the unaided eye, and slightly pitted or punctate under a 

 strong lens. The fragment of the cephalon has a length of 16 mm. 



Formation and Locality. Upper Cambrian: (061) A dense black limestone in 

 the uppermost limestone member of the Kiu-lung group [Blackwelder, 19070, pp. 37 

 and 41 (third list of fossils), and fig. 10 (bed 13), p. 38], 3 miles (4.8 km.) south- 

 west of Yen-chuang, Shan-tung, China. 



Collected by Li San. 



Chuangia nais Walcott. 

 Plate 1 6, Figure i. 



Chuangia nais WALCOTT, 1911, Smithsonian Misc. Coll., vol. 57, No. 4, pp. 84-85, plate 15, fig. 6. 

 (Described and discussed as a new species essentially as below.) 



This is a large species that is represented by a part of the central portions of 

 the cephalon. Glabella subquadrangular, moderately convex, narrowing slightly 

 toward its broadly rounded front ; without glabellar furrows as far as can be deter- 

 mined; occipital furrow shallow, rather broad, and nearly transverse; occipital 

 ring gently convex, and slightly wider toward the center; dorsal furrow shallow and 

 clearly defined. 



Fixed cheeks about two thirds the width of the glabella, nearly flat between 

 the glabella and the palpebral lobes, and sloping downward in front to the frontal 

 rim, and back to the posterior furrow; palpebral lobe small; palpebral ridge narrow, 

 low, and situated so as to cross the fixed cheek obliquely where the downward slope 

 to the front is most marked ; postero-lateral limb long, with a strong furrow within 



