18 BULLETIN 16 4, UNITED STATES NATIONAL MUSEUM 



SANTAO FORMATION 



Type locality. — Above the second tunnel near San-tao-kang-tzu, 

 1.5 miles north of the Pen-hsi-hu colliery. (PI. 5.) 



Characters. — Moderately thick-bedded, ^ray, arenaceous limestones 

 crossed irregularly by many fissures now filled by calcite. 



Thickness and geographic distribution. — The Canadian Santao 

 formation, so far as now known, appears to be undeveloped in the 

 Kuantung and Pechili districts. In the Tai-tzu-ho district, on the 

 contrary, it has a comparatively wide distribution. 



In the Yen-tai subdistrict, it occurs on the eastern lower slope of 

 Wu-ting hill, 3 miles south of the Yen-tai colliery, where it is esti- 

 mated as about 60 m (196.8 feet) thick. In the Pen-hsi-hu subdistrict, 

 it outcrops above the second tunnel near San-tao-kang-tzu, and here 

 it has a thickness of about 80 m (262.4 feet). It also appears near 

 Tai-chia-pu-tzu, 2 miles west of Chiao-tou station on the Antung- 

 Mukden line, where it is estimated at about 60 m (196.8 feet). In the 

 vicinity of Niu-hsin-tai it occurs on the upper slope of the San-f ang- 

 la-tzu hill, 1.8 miles east of the Niu-hsin-tai colliery, and again an 

 equal distance west of the same place on the western slope of the Wo- 

 lung ridge, and at this place it is about 60 m (196.8 feet) in thickness. 



Unfortunately I have not yet been able to find Santao fossils in 

 the Hsiao-shih subdistrict, but I think further search may yield 

 characteristic examples. 



Stratigraphic relations. — The Santao rests apparently conformably 

 on the Ozarkian Pingchou formation at all outcrops. On the eastern 

 lower slope of Wu-ting hill the lower Chazyan Kangyao is situated 

 between the Santao and the Wuting formations, but exact boundaries 

 have not yet been established. In fact, at most localities the upper 

 and lower boundaries of the former are not well defined, since all 

 adjacent formations are lithologically similar. 



Fauna. — From the fossil locality of the Santao formation on the 

 eastern lower slope of Wu-ting hill I have collected the following 

 species: Hortnotoma sp. and Calathiwii frechi, new species. 



In the gray limestone beds above second tunnel, north of Pen- 

 hsi-hu, a larger fauna was collected (pi. 3) : 



Calathium frechi, new species. 

 Anthaspidellal planulata, new species 

 Anthaspidella'i radiata, new species. 

 Polytoechiat tapvensis, new species. 



In addition I collected Piloceras manchuHense and fragments of 

 other species near Tai-chia-pu-tzu, 2 miles west of the Chiao-tou 

 station, and near the Niu-hsin-tai colliery. 



Correlations. — The fossils listed above show that the Santao rep- 

 resents the North American uppermost Canadian. The Santao for- 



Piloceras manchuriense, new species. 

 Penhsioceras fusiforme, new genus and 



species. 

 Camcroccras cf. styliforme Grabau. 



