294 RESEARCH IN CHINA. 



of the Baltic provinces of Russia. These two formations are essentially 

 equivalents of American faunas included in the Mohawkian division of the 

 Ordovician, and we recognize in this Chinese fauna several species among 

 the brachiopods which are identical with or closely allied to North American 

 Mohawkian forms. The fauna presents in its entirety a mingling of Baltic 

 and North American forms, although the Baltic element is much the more 

 pronounced. In age the fauna is clearly not younger than the Mohawkian 

 faunas of North America, and it may be safely considered as the essential 

 time equivalent of the Black River limestone of North America and of the 

 Vaginatus limestone of Russia. 



EXPLANATION OF PLATE 25. 



i- 2. Strophomena sp. undt. Weller (p. 281). 12-16. Dalmanites testudinaria (Dalman) (p. 283). 



3- 6. Orthis calligramma Dalman (p. 282). 17-18. Clitambonites chinensis Weller (p. 283). 



7- 9. Triplecia polol (Martelli) (p. 281). 19-20. Dalmanella subcequata (Conrad) (p. 283). 



10-11. Plectorthis willisi Weller (p. 283). 21-24. Hemipronites tenuistriata Weller (p. 284). 



EXPLANATION OF PLATE 26. 



1. Cornulites sp. undt. Weller (p. 285). n. Proelus? sp. undt. Weller (p. 289). 



2. Crytodonta ? sp. undt. Weller (p. 285). 12. Pterygometopus ? sp. undt. Weller (p. 289). 

 3-4. Asaphus sp. cf. A. expansus Dalman (p. 287). 13. Isolelus ? sp. undt. Weller (p. 288). 



5. Asaphus asiaticus Weller (p. 287). 14. Asaplms sp. undt. Weller (p. 288). 



6. Asaphus Icevis Weller (p. 287). 15. Isotelus sp. undt. Weller (p. 288). 



7. Asaphus chinensis Weller (p. 287). 16. Ampyx chinensis Weller (p. 285). 



8. Megalaspis minor Weller (p. 288). 17-18. Bathyurus sp. undt. Weller (p. 285). 



9. Asaphus sp. undt. Weller (p. 288). 19-20. Asaphus taningensis Weller (p. 286). 

 10. Illcenus ? bronteaides Weller (p. 289) 21-22. Asaphus blackwelderi Weller (p. 286). 



