i'ol I. Sun — Camhrian Faunas of North China (iv) 23 



"Horizon and Locality: — In the Upper Cambrian Fengshan formation of 

 Yeh-li: collected by Mr. H. C. T'an" (Grabau). 



Dr. Walcott referred the specimen figured by Kayser to Lingulella davisii 

 (JMcCoy), from which however our species is quite different. McCoy's species is charac- 

 terized by relatively greater width, V)y a more nearly rectangular umbonal region, and 

 by the lack of the characteristic ornamentation found in our species, though this may 

 also be absent in the specimens figured by Kayser. 



Genus ACROTHELE Linnarson 

 Acrothele cheni Sun (sp, nov.) 



Plate I, Figs. Ha-llb. 



All the specimens representing this species are flattened by compression on the 

 argillaceous shale, and are also more or less distorted. 



General form subcircular except for the straight posterior margin. Pedicle valve 

 flat due to compression with the apex 2.5 mm. from the posterior margin. A triangular 

 false area extends from the apex to the margin; it is defined by a slight depression and 

 a low ridge at the outer edges ; surface marked by numerous more or less regular lines of 

 growth, but not marked by radiating lines. 



Nothing is known of the interior characters. 



This species is characterized by its subcircular form, numerous concentric growth 

 stria3 and the position of the apex. 



A shell 10.5 mm. in width has a length of 9.5 mm. Avhile another measures 9 mm. 

 in length and 9.3 in width. 



Horizon and Locality: — ^Middle Cambrian: from Changshan shale of Chao- 

 kuo-chuang, Luan-Hsien, Chihli. Collected by S. Chen W. M of class 1925 of the 

 Geological Institute of the National University. 



Genus NiSSUSIA Walcott 

 Nissusia hayasakai Sun (sp. nov.) 



Plate I, Fig. 12. 



Shell semioval with the hinge line a little shorter than the greatest width of the 

 shell; surface of shell marked by radiating ribs and also by a few concentric lines. 



