NO. 1415. CAMBRIAN FAUNAS OF CHINA— WALCOTT. 21 



The elliptical section and the line, raised, transverse stria? serve to 

 distinguish this species from any other known to me. 



Formation and locality. — Middle Cambi-ian, central portion of 

 Chang Hsia formation, in limestone nodules at the base of a stratum 

 of green shale, a local phase of the Chang Hsia oolite formation; 3 

 miles south of Kao Chia Pu and 3 miles southwest of Yen Chuang, 

 Hsin Tai, Shangtung, China. 



Collected ])y Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



ORTHOTHECA DORIS, new species. 



Shell elongate, slender, and regularly tapering. Transverse section 

 oval or circular; in the type and only specimen the shell is somewhat 

 ci'ushed, which leaves the original form in dou))t. The dorsal face 

 appears to have been moderately convex, with rounded lateral angles 

 that pass into the convex, rounded ventral side. Transverse stritv and 

 lines of growth indicate that the aperture was probaVdy transvei'se. 

 Shell apparently strong. 



Surface of shell transversely or concentrically marked b}- lines of 

 growth, with more or less irregular stria? between them; in addition 

 there is a finely pitted surface between the stria?, and sometimes on 

 them, that gi\os a very peculiar aspect to the surface under a strong- 

 lens. 



The fragment representing this species has a length of 1.U mm., W' ith 

 a transverse diameter at the larger end of 5 nmi. 



This species is characterized by the peculiar, irregularly pitted 

 surface. 



Forination and locality. — Middle Cambrian; collected from river 

 drift rock on gravel bar in the Lan Ho, 1 mile south of Chen I*ing 

 Hsien, southeastern Shensi, China, near the extreme southeastern 

 corner of the Province of Shensi, adjoining on Hupeh and Ssuch" uan. 



Collected by Bailey Willis and P^liot Blackwelder, of the Carnegie 

 Institution of Wasiiington Expedition to China. 



ORTHOTHECA, species undetermined. 



Fragments of a small, elongate, slender Orthotheca occur in the 

 upper Cambrian. The .species has a transverse section much like that 

 of O. daalis., except that the dorsal face is much broader, which gives 

 a rounded, subtriangular outline to the section, resembling in this 

 respect 0. cyrene, but the latter has a shallow groove on the dorsal 

 face which is absent in the fragments under consideration. 



Formation and locality. — Upper Cambrian, upper part of Chao Mi 

 Tien formation; Pagoda Hill, 1 mile west-southwest of Tai An Fu, 

 Hsin Tai, Shangtung, China. 



Collected by Eliot Blackwelder, of the Carnegie Institution of 

 Washington Expedition to China. 



