twexhofel: expedition to the Baltic provinces. 339 



tion is hence made wath greater confidence. It is also possible that 

 the upper beds of the St. Johannis formation have an equivalence 

 with the Lower Ludlow of England. 



As is to be expected, the case is not so sharply clear for the American 

 sections; but no less than twenty species occur in the American 

 Niagaran ^ or are represented by forms closely related. These are : — 



1. Hindia fibrosa. 



2. Cystiphyllum cylindricum. 



3. Favosites gothlandicus. 



4. hisingeri. 



5. Halysites catenularia. 



6. Paleocyclus porpita. 



7. Atrypa reticularis. 



8. C\Ttia exporrecta. 



9. Dalmanella elegantula. 

 10. Eospirifer radiatus. 



IL Leptaena rhomboidalis. 



12. Meristina tumida. 



13. Plectambonites transversal is. 



14. Rhipidomella hybrida. 



15. Rhynchotreta cuneata. 



16. Schuchertella pecten. 



17. Spirifer crispus. 



18. Wilsonia wilsoni. 



19. Calymene tuberculata. 



20. Encrinurus punctatus. 



There is little doubt that the above list will be lengthened when 

 the St. Johannis fauna has been comparatively studied. Heliolitidae 

 are present which are quite similar to the American species and such 

 is the case with other forms of other groups. Since the fauna has by 

 no means been carefully studied, only a few over fifty species having 

 been recognized, this makes over thirty per cent of the fauna which 

 has been recognized in the American Niagaran. It is also possible that 

 the St. Johannis formation extends a little higher than the highest 

 beds of the Niagaran. 



In the Anticosti section the formation may firnd representation in 

 the upper portion of the Jupiter River formation and almost certainly 

 in the Chicotte, but the Anticosti series does not extend high enough 

 to completely represent the Russian formation. 



1 Niagaran as here used excludes the Clinton. 



