100 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxix. 



Width of valve 1 mm.; length 0.75 mm.; depth about 0.25 mm. 



This species is distino-uished from B. sterope by the difierence in the 

 form of the anterior cardinal angle and the position of the ocular 

 tubercle. The latter is in about the same position as the tubercle on 

 B. hcrqerou!, but B. hergeronl is quite different in its outline and 

 convexit} . 



Fonnatlon and locality. — ^Middle Caml)rian; compact, bluish-g-ray., 

 thin-bedded limestone; from shingle on gravel bar in the Lan Ho, 1 

 mile south of Chen Ping Hsien, southeastern Shensi, China. 



Collected by Bailey Willis and Eliot Black welder, of the Carnegie 

 Institution of Washington Expedition to China. 



BRADORIA ERIS, new species. 



General outline obliquely semicircular. Hinge line straight; ante- 

 rior cardinal angle about 70^; posterior cardinal angle slightly obtuse; 

 anterior margin nearly straight to where it merges into the rounded 

 lower margin; posterior margin gently rounded from the angle down 

 to where it merges into the lower margin. Surface moderately con- 

 vex, with the highest point at the tubercle a little in front of the cen- 

 ter; a verv narrow rim extends from the posterior cardinal angle 

 around to the anterior side, where it broadens out and continues to 

 the anterior cardinal angle; a slight narrow ridge extends obliquely 

 inward a short distance from the anterior cardinal angle to a furrow 

 that extends from the hinge line at right angles a short distance; the 

 ridge and furrow outline a small lobe; from the inner angle forme'd 

 l)y the furrow and ridge described a very narrow ridge extends down- 

 w^ard subparallel to the anterior margin to the base of a strong, 

 elevated tubercle or spine that is situated on the anterior third a little 

 in advance of the transverse center of the valve. 



Under a strong lens the surface appears to be slightly roughened 

 b}^ shallow puncta\ 



Width, 2 mm.; length, 1.5 mm.; 'depth, about 0.5 mm. 



This species differs from Bradoria sterope in the outline of its valve 

 and the presence of an elevated tubercle near the center. 



Foi'vMtUm and locality. — Middle Cambrian; compact, bluish-gray, 

 thin-bedded limestone; from shingle on gravel bar in the Lan Ho, 1 

 mile south of Chen Ping Hsien, southeastern Shensi, China. 



Collected by Bailey Willis and Eliot Blackwelder, of the Carnegie 

 Institution of Washington Expedition to China. 



BRADORIA FRAGILIS, new species. 



Hinge line nearly straight, about one-fffth shorter than the width of 

 the valve. Posterior cardinal angle ol)tuse, with the marginal curve 

 long and passing into the broad curve of the lower end of the valve; 

 anterior cardinal angle about 75"^, with the anterior margin nearly 



