DESCRIPTION OF GENERA AND SPECIES. 167 



Formation and Locality. Middle Cambrian: (077) Limestone interbedded in 

 green shales not more than 300 feet (90 m.) above the Man-t'o shales [Willis and 

 Blackwelder, 1907, p. 144 (first list of fossils)], 4 miles (6.4km.) southeast of Yau-t'o, 

 near Wu-t'ai-hien, Shan-si, China. 



Collected by Eliot Blackwelder. 



Lisania spp. undt. (a), (b). 

 Plate 15, Figures 20, 21. 



Two pygidia are illustrated by figures 20 and 21 that may belong to this genus. 



The specimen represented by figure 20 is from Locality C30, Middle Cambrian, 

 layer in black oolite of the Ch'ang-hia limestone [Blackwelder, 19070, p. 33 (part of 

 first list of fossils)], 25 feet (7.5 m.) above the second cliff at an elevation of 1,700 

 feet (568.9 m.) on top of the long north and south ridge at Ch'ang-hia, Shan-tung, 

 China. 



That represented by figure 21 is from Locality C41, Upper Cambrian, lower 

 part of the Ch'au-mi-tien limestone [Blackwelder, 19070, p. 36 (part of the first list 

 of fossils)], 2.7 miles (4.3 km.) southwest of Ch'au-mi-tien, Shan-tung, China. 



Collected by Eliot Blackwelder. 



Genus SOLENOPLEURA Angelin. 



Solenopleura ANGELIN, 1854 (edition 1878), Pal. Scandinavica, pt. i,p.26. (Described as a new genus.) 



For the purposes of comparison three views are given on plate 17, figures 12, 

 i2a-6, of a cranidium of Solenopleura holomctopa Angelin [1854 (ed. 1878), p. 26, 

 plate 1 8, figs. 8, 8a] obtained by photographing a specimen from the type locality at 

 Andrarum. The strongly tuberculated surface is shown by figure 1 2c, a photograph 

 of an associated free cheek. 



Solenopleura agno Walcott. 



Plate 17, Figure 15. 



Solenopleura agno WALCOTT, 1905, Proc. U. S. Nat. Mus., vol. xxix, p. 89. (Described as a new species 

 essentially as below.) 



General form of cephalon, exclusive of free cheeks, transversely subrhomboidal, 

 convex. Glabella as long as the width at its base, the sides converging from the base 

 toward the rounded front, so as to narrow the glabella about one-fourth; a very 

 slight trace of a short, posterior pair of furrows can be seen by reflected light ; occip- 

 ital furrow well defined by the downward curvature of the posterior margin of the 

 glabella and rising of the surface of the occipital ring; the latter is narrow at the 

 sides, gradually widening toward the center, which is most elevated a little in front 

 of the posterior margin; dorsal furrow narrow, but clearly defined at the sides in 

 front of the glabella. 



Fixed cheeks about one-half the width of the glabella at the center, rather 

 convex, and sloping somewhat abruptly to the frontal rim ; palpebral lobe small, situ- 

 ated about midway of the cheeks; postero-lateral limbs unknown; frontal limb very 

 narrow in front of the glabella, convex, and curving down to the broad groove within 

 the strong, rounded frontal rim. 



Surface marked by low pustules that give it a roughened appearance. 



The type and only specimen of the cephalon in the collection has a length of 

 6 mm. 



This species is characterized by its broad, short glabella, narrow frontal limb, 

 and peculiar, granulose surface. 



