(iv) 20 Palaeontologia Sinica Ser. B. 



1919 Oholus? sp. indet. Walcott, Cambrian Brachiopoda p. 6'2. 



1922 Obolus hianhsiense Qx&h&xi (mss.) 



1923 Obolus luanhsiense Grabau, Sun. Bull. Geol. Soo- China, Vol. H, p. 9s (listed). 



"Shell moderately large of subtriangular outline and moderate to strong con- 

 vexity ; length slightly less than the gieatest width which is in the anterior third of the 

 shell. Posterior l>orders nearly straight meeting at the beak approximately in a right 

 angle. Antero -lateral hordei's rounded, front straight or more rarely faintly sinuate. 

 Convexity most pronounced in the umbonal region, the shell becoming flattened tOAvards 

 the front. 



"Surface marked by lines of growth which are fine and regular in the young 

 shell giving the surface a smooth appearance, but become coarser and more of the nature 

 of faint concentric wrinkles in the adult portion, where the shell is also sometimes charac- 

 terized by a few faint radiating wrinkles. Exceedingh' fine radiating lines are shown 

 under a high power lens on the young shell. 



^^ Dimensions. Three individuals measure respectively : length 7.6 mm., 5.6 mm., 

 6.4 mm., width 8. mm., 5.1 mm., 6.5 mm. 



Horizon and Locality: — Associated with LmguleUa kayseri Grabau in the thin- 

 bedded limestone layers of the Fengshan formation of Upper Cambrian age at Yeh-li, 

 Luan-Hsien, Chihli; collected by H. C. T'an. 



' 'This species is not unlike Lingida petalose Hicks from the Arenig of Whitesand 

 Bay (Davidson: Silurian Brachiopoda, pi. XLIX, fig. 30, p. 337). That species is 

 described as broadest in the middle, but some of the specimens figured by Davidson 

 show the greatest width in the anterior third. In this respect, as well as in general 

 shape and in size, they agree fairly well with our species." (Grabau). 



Genus LlNGULELLA Salter 



Lingulella dimorpha Sun (sp. nov.) 



Plate I, Fig. 8a-8b. 



Shell of medium size, and subrectangular form; length and width approximately 

 as six to five. Sides of ^hell nearly parallel, but gently curved, frontal margin rounded 

 at the sides, straight in the center; posterior margins straight on either side of the beak, 

 meeting at the latter at an angle of about 150". 



