27 



Orthoccras sp. 



4. Seven and a half miles SSE of Siij-tai-hsien^' ; a few hundred feet be- 

 low the top of the Tsi-nan limestone (Wirj.is and Bi.ackwki.der ; ident. b\' 

 S. Wefxer/' 



Orthoccras sp. and a gastropod. 



5. NE of Tsai-kia-chuang'^ ; Tsi-nan limestone (Willis and Black- 

 welder ; ident. by S. Weller).^^ 



Orfhis ? or DaliiuincIIa ? sp. 

 Mac/iirca ? or Hclicostoma ? sp. 

 LopJiospira sp. 

 Ort hoccras sp. 

 Asa films ? sp. 



6. Two and seven-tenths miles SW of Yen-chuang"''^ ; upper part of the 

 Chau-nii-tien limestone (Willis and Blackwelder ; ident. by S. Weller."^ 



Orthoccras sp. 



7. Five and a half miles SW of Tsi-nan ; Tsi-nan limestone (Willis and 

 Blackwelder ; ident. by S. Weller).'" 



Strophomcna sp. 

 Ortlioccras sp. 



8. A gravel in the valley of a dry stream 4.8 miles WSW of Tsi-nan 

 (Willis and Blackwelder ; ident. by S. Weller)^' 



Orthoccras sp. 



From these fossils, Girty concludes that the Tsi-nan limestone may belong 

 somewhere in the middle division of the Ordovician.''' 



Willis and Blackwelder proposed to define the "Sinian formation " more 

 accurately than Richthofen, and marked the Tsi-nan limestone as the Upper 



1) S. Weller: I.e. p. 279. 



3) 5J;t^ffi 



4) S. Weller: I.e. p. 279. 



5) aa- 



5) S. Weller: Lc. p. 280. 



7) S. Weller: I.e. p. 280. 



8) S. Weller: I.e. p. 280. 

 g) S. Weller: I.e. p. 279. 



