76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



excepir for the slightly flattened dorsal side. Operculum unknown. 

 Shell rather thick, and with a smooth surface. 



The largest specimen in the collection has a length of 5 mm. 



Observations. — This species is distinguished from other Chinese 

 forms by its rounded tube and smooth surface. It is the representa- 

 tive in form of the American Orthotheca communis Billings.' 



Orthotheca glabra occurs abundantly in association with Hyolithcs 

 cybele Walcott, in the Dorypyge richthofeni zone of Manchuria. 

 Some of the shells have a long, slender terminal section to the tube 

 that is more or less slightl}- curved. It is so slender and round that 

 it suggests the tube of Hyolithellns.^ 



Formation and locality. — Middle Cambrian: (C71) massive cliff 

 making limestone in the central portion of the Ki-chou formation, 4 

 miles (6.4 km.) southwest of Tung-yii ; and (C72) thin green gray 

 limestone interbedded with ocherous and green clay shales, overlying 

 the massive oolite in the Ki-chou formation, 4 miles (6.4 km.) east 

 of Fang-lan-chon ; both in Shan-si, China. 



Collected by Eliot Blackwelder. 



Also (35n) Middle Cambrian: Fu-chou series; limestones near 

 the base of the series 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. 



ALBERTELLA PACIFICA, new species 

 Plate 14, fig. 6 



Of this form only one fragment of the pygidiu'm was found in the 

 collection from Manchuria. This is so characteristic that I do not 

 hesitate to identify it as the pygidium of an Albertella although 

 stratigraphically it occurs at a higher horizon in the Middle Cambrian 

 than the American species of the genus. 



A pygidium illustrated by M. Barrande as Paradoxides desidcratus 

 Barrande ^ may possibly belong to a species of Albertella. The axial 

 lobe of the pygidium has seven rings and a terminal section and the 

 pleural lobes have lateral spines. 



Formation and locality. — Middle Cambrian: (36f) Fu-chou series; 

 about 1000 feet (305 m.) above the white quartzite, collected in a 



^ Tenth Ann. Rept. U. S. Geol. Survey, 1891, pi. 77, figs. 3, 3a-g. 

 * Idem, pi. 79, fig. I a. 



^ Barrande, 1852, Systeme Silurien du Centre de la Boheme, Vol. I, pi. 12, 

 fig- 15- 



