FORMATIONS AND FOSSILS OF SOUTH MANCHUIIIA 15 



River fauna and is therefore to be regarded as of that age. This 

 fauna also shows that it is to be correlated with part of Grabau's 

 Machiakou limestone in Chihli to the southwest, and on the other 

 hand, to the east, with part of Kobayashi's Unkaku on Bantatsu 

 hill, east of Heijo, North Korea. 



Even though, as discussed in the paragraphs dealing with nomen- 

 clature, the Ssuyen formation apparently is the eqiuvalent of about 

 the upper two-thirds of Kobayashi's Toufangkou series (that is, 

 it corresponds with his zones X and IX), a new formational name 

 is necessary to conform to the rules governing stratigraphic terms. 



The Ssuyen formation also corresponds to the upper part of 

 Matsushita's Aigawa series. 



WUiTING FORMATION 



Type locality. — The top and southern slope of Wuting hill, 3 

 miles south of the Yen-tai colliery. (PI. 4.) 



GharacteT. — ^This formation consists essentially of moderately 

 bedded gray to dark limestones with some edgewise conglomerates. 

 In its lower portion arenaceous limestone bands with numerous 

 fossils are present : 



Thickness. — As follows : 



Kan-tao-tzu section of the Kuantung district 160m (524.8 feet). 



Ma hill near Wu-hu-tsui colliery, estimated 160m (524.8 feet). 



Shan-ping-chou section, 8 miles east of Liao-yang, about 280m (918.4 feet). 



On the top and southern slope of the curved ridge, just west 



of Hui-kou, about 200m (656 feet), 



Pen-hsi-hu section, about 80m (262.4 feet). 



Niu-hsin-tai section, about 80m (262.4 feet). 



Hsiao-shih subdistrict, estimated about 100m (328 feet). 



Geograyhic distribution. — ^In the Kuantung district, the Wuting 

 formation occurs in both the western and eastern portions of Kan- 

 tao-tzu Island; also near Wan-chia-tung, 1 mile southwest of 

 Aigawa, and on the southwestern lower slope of the Lao-hu ridge, 1 

 mile north of Aigawa. In the Chin-chia-cheng-tzu area, it is present 

 on Ma hill, on the outer lower slope of San-leng hill, and at the 

 eastern end of Tai-tzu hill. 



In the Liaoyang-Yentai subdistrict the outcrops are on Yu-ho hill, 

 8 miles east of Liao-yang, and on the western lower slope of the 

 curved ridge, just west of Hui-kou. It also occurs on the top and 

 southern slope of Wu-ting hill and its environs. 



In the Pen-hsi-hu subdistrict it is present on the ridge north of 

 Tai-chia-pu-tzu, 2 miles west of Chiao-tou station; and also near 

 Ta-pu and San-tao-kang-tzu, just north of the Pen-hsi-hu colliery. 

 In the vicinity of the Tao-yuan-kou colliery, it is distributed near 



