FORMATIONS AND FOSSILS OF SOUTH MANCHUHIA 27 



Canadian 



Santag formation: 



Moderately thick-bedded, gray, arenaceous limestones with many 

 irregular calcite veins, in layers 2 to 10 cm thick, 80 m (262.4 feet). 



FaiwML. — On the top of the second tunnel, 1 mile north of Pen- 

 hsi-hif, a good fossil locality occurs from which I collected the fol- 

 lowing important, characteristic Canadian fossils : 



Anthaspidellaf planulata, new species. 

 Anthaspi^lla? radiata, new species. 

 Polytoechia? tapnensis, new species. 

 Cameroceras cf. styliforme Grabau. 



Piloceras manchuriense, new species. 

 Penhsioceras fusiforme, new genus and 

 species. 



TAO-YUAN-KOU SECTION 



In the vicinity of the Tao-yuan-kou coal field, the Ordovician 

 strata are very well exposed, but, unfortunately, many comparatively 

 strong faults have disturbed and scattered the outcrops, making nec- 

 essary a generalized and somewhat arbitrary section. The strata 

 that outcrop on the Lao-hu-ti-kou ridge have a synclinal structure, 

 while those at Lung-wan-tien and near Huang-kan-kou are in a 

 tilted block dipping 20° or 30° to the west. This section is essen- 

 tially the same as that of Pen-hsi-hu, 5 miles southwest of this area, 

 except that the Canadian Santao formation is lacking. 



Ordovician 



SSUTEN FORMATION : 



1. Moderately thick-bedded, black to light gray limestone, in lay- 

 ers 5 to 20 cm thick, with interbedded thin edgewise conglomerate 

 and dolomitic layers, 40-150 m (131.2-492 feet). 



Fav/na. — A good fossil locality occurs in the valley of Yao-tzu-ku- 

 pan-kou, where I collected Maclurites higsbyi (Hall) and Armeno- 

 ceras shimisui, new species. 



2. Moderately thick-bedded, light gray, buff-weathering, arena- 

 ceous, dolomitic limestone in layers 4 to 20 cm thick. These beds 

 become thinner as compared with those of the Pen-hsi-hu and Shan- 

 ping-chou sections, about 20 m (65.6 feet). 



Total Ssuyen formation, 170 m (557.6 feet). 



WUTING FORMATION : 



Moderately thick-bedded, gray to dark limestone, interbedded with 

 thin edgewise conglomerate and arenaceous limestone beds varying 

 in thickness from 1 to 30 cm, about 120 m (393.6 feet) . 



Fauna. — ^From the arenaceous beds comparatively well-preserved 

 fossils have been obtained near Ku-chia-tsu: EapMstoma cf. aequi- 

 laterum Koken? and undetermined brachiopods. 



