74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



varying width. A dorsal valve shows a few fine, faint, radiating 

 ridges. 



A ventral valve 3 mm. in width has a length of 2.75 mm. and a 

 height of I m.m. A dorsal valve with a width of 2.5 mm. has a length 

 of 2 mm. and a height of 0.5 mm. at the beak. 



Observations. — In form the ventral valve of this species is not 

 unlike that of Micromitra sciilptilis (Meek) except that it is not as 

 elevated and its surface is quite different. It is associated with M. 

 sciilptilis and the two varieties of Micromitra {Iphidella) panmila, — 

 oplnrensis and maladensis. 



Formation and locality. — Middle Cambrian: Fu-chou series; (35n 

 and 35r) limestones and (36d) shales near the base just above the 

 white quartzite, collected in a low bluff on the shore of Tschang- 

 hsing-tau island, east of Niang-niang-kung, Liau-tung, Manchuria. 

 China. 



Collected by J. P. Iddings and Li San. 



LINGULELLA MANCHURIENSIS, new species 



Plate 14, figs. 2, 2a 



This species and Lingulella marcia belong to a group of small, 

 elongate, oval shells that are represented in the Rocky Mountain 

 Province Cambrian fauna by Lingulella mamticvda (White) and in 

 the Atlantic Province fauna by L. ataz'a (Matthew), L. collicia 

 (Matthew), L. ferruginea (Salter), L. nanno (Walcott), and a num- 

 ber of similar forms. Lingulella manchuriensis appears to be most 

 nearly related to L. similis (Walcott). It differs in the broader, more 

 rounded posterior half of the ventral valve. 



The average length of the ventral valve is 3 mm. among the large 

 number of shells that occur in both limestone and shale. 



Formation and locality. — Middle Cambrian: (35p) Fu-chou 

 series; shales about 80 feet (24 m.) above the white quartzite, col- 

 lected in a low bluff on the shore of Tschang-hsing-tau island, east 

 of Niang-niang-kung, Liau-tung, Manchuria, China. 



Collected by J. P. Iddings and Li San. 



LINGULELLA MARCIA, new species 



Plate I, figs. 3, 3a 

 This species is one of the small forms allied to the group of simi- 

 lar shells mentioned under L. manchuriensis. It differs from the 

 latter species in being relatively broader in outline, with the sides 

 of the valves less uniformly arched, and in having a more broadly 

 rounded frontal margin. 



