DESCRIPTION OF GENERA AND SPECIES. 163 



bclla; the glabella of P. bia has a length of 6 mm. with a width at the center of 

 3 mm., while P. lotos, with a length of 5 mm., has a width at the center of nearly 4 mm. 



Formation and Locality. Upper Cambrian : ((' 5(5) Lower part of Ch'au-mi-tien 

 limestone, 25 feet (7.5 m.) below the top of Pagoda Hill [Blackwelder, igoya, p. 42 

 (part of last list of fossils)], i mile (1.6 km.) west of Tsi-nan, Shan-tung, China. 



Collected by Eliot Blackwelder and Li San. 



Pagodia macedo Walcott. 



Plate 15, Figure 13. 

 Pagodia macedo WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 66. (Described as a new species.) 



This species is represented by a single specimen of the cephalon, exclusive of the 

 free cheeks. Glabella elongate, subquadrangular, narrowing very slightly toward 

 the broadly rounded, nearly transverse front, as indicated by the cast of the interior 

 of the crust ; surface marked by two pairs of shallow furrows that penetrate a short 

 distance on each side and separate the glabella into three subequal lobes ; occipital 

 furrow rounded and strong; occipital ring unknown; dorsal furrow strong, rounded, 

 and clearly separating the moderately convex glabella from the sloping fixed cheeks. 



Fixed cheeks slightly convex, sloping gently from the dorsal furrow to the 

 palpebral lobe, more rapidly to the furrow within the posterior margin, and anteri- 

 orly to the front margin ; palpebral lobes situated about midway between the front 

 and the posterior margins of the cephalon, small and short, not much over one-fifth 

 the length of the cephalon; frontal rim narrow, wire-like, and separated from the 

 glabella and fixed cheeks by a rounded furrow of moderate depth. 



The crust is rather thick, the outer surface marked by scattered, shallow punctae, 

 with very fine punctae, as shown by a strong lens, between them. 



Length of cephalon, exclusive of occipital ring, 7.5 mm. 



This species is closely related to Pagodia lotos [p. 163]. It differs in the form 

 of the frontal rim and the more uniform slope of the glabella toward the front. 

 From P. bia [p. 161] it differs in the more rapid downward slope of the front of the 

 glabella and in the parallel or slightly contracting sides of the glabella. 



Formation and Locality. Upper Cambrian: (C34) Purplish-gray limestone about 

 100 feet (30 m.) above the base of the Ch'au-mi-tien formation [Blackwelder, 19070, 

 p. 36 (part of first list of fossils)], in road at northeastern corner of small village near 

 Ch'au-mi-tien, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Genus LISANIA Walcott. 



Limiiia WALCOTT, 1911, Smithsonian Misc. Coll., vol. 57, No. 4, pp. 82-83. (Described and discussed 

 as a new genus essentially as below.) 



Cranidium subquadrate in outline, exclusive of postero-lateral limbs. Glabella 

 with slightly converging sides, broadly rounded in front and curving gently down 

 to a narrow furrow separating it from the frontal border, without distinctly marked 

 glabellar furrows ; occipital furrow distinct ; occipital segment strong. Fixed cheeks 

 narrow ; palpebral lobe above the eye nearly one-third the length of the cephalon ; 

 palpebral ridge usually defined to the edge of the dorsal furrow beside the glabella. 

 Frontal border slightly convex and separated from the fixed cheeks and glabella by 

 a narrow, shallow, but distinct furrow. 



The associated free cheeks have a strong genal spine, and associated pygidia 

 a strong central axis marked by three or four transverse rings and a terminal section. 



Surface smooth or slightly roughened by very fine shallow pits. 



