312 bulletin: museum of comparative zoology. 



tions are quite similar to those of Esthonia. The faunal elements 

 common to the two regions, however, are not so many as one could 

 wish. 



A correlation is most readily made if the Borkholm formation be 

 taken as a point of departure. It has its closest faunal relations with 

 the Ellis Bay formation of the Anticosti section, where are found the 

 following identical or closely related forms : — 



1. Calapoecia canadensis. 



2. Clathrodictyan vesiculosum. 



3. Halysites catenularia. 



4. Paleofavosites asper. 



5. Protaraea vetusta (this form in Esthonia occurs in the Lyck- 

 holm only). 



6. Zaphrentis affinis (a similar form in the Borkholm is called 

 Streptelasma elongatum). 



7. Corynotrypa dissimilis. 



8. Hallopora elegantula, var. nov. 



9. Glauconema strigosa. 



10. Xematopora lineata. 



11. Phaenopora ensiformis. 



12. Protocrisina exigua (Charleton, not Ellis Bay). 



13. Ptilodictya gladiola. 



14. Sceptropora facula (Charleton, not Ellis Bay). 



15. Stomotopora arachnoidea (not in Borkholm, but Lyckholm). 



16. Atrypa marginalis. 



17. , Clitambonites verneuili di versus (Shaler). 



18. Platystrophia regularis Shaler (European type with two plica- 

 tions in the sinus and three on the fold). 



19. Leptaena rhomboidalis. 



20. Pseudolingula elegantula (Shaler) (P. quadrata in the Lyck- 

 holm). 



21. Plectambonites sericeus. 



22. Byssonychia sp. nov. 



23. Calymene meeki Foerste. 



24. Encrinurus multisegmentatus. 



This constitutes a total of twenty-four out of ninety-five species, 

 over twenty-five per cent of the Borkholm fauna, and coupled with 

 this, is the further fact that each witnesses the occurrence in great 

 numbers of a multitude of tabulate corals of Silurian aspect, which in 



