TWENHOFEL: EXPEDITION TO THE BALTIC PROVINCES. 305 



and Ptilodictya flabellata from the same locality is referred by Bassler 

 to the Borkliolm. 



Since it is really the lower beds which contain nearly all the Bryozoa 

 described by Bassler and few are from the upper beds, it must be 

 inferred that Bassler's conclusion in so far as it relates to a time break 

 arose from a mislabeling of the specimens as to stratigraphic position, 

 and he " now agrees that not only the Upper Lyckliolm is of Richmond 

 age, as stated in his work, but that the Lower Lyckliolm also should 

 be so correlated." ' 



It appears very probable that the Lyckholm rests on the Wesenberg 

 or the Kegel in apparent conformability, although the Pallokiill 

 Krug and Pallokiill Chapel occurrences throw some doubt on this 

 conclusion. There is, however, a sharp lithic and a considerable 

 faunal change in passing from the Wesenberg to the Lyckholm. Of 

 the great array of Lyckholm corals there is nothing seen in the Wesen- 

 berg. 



The species whose names follow are common to the Lyckliolm and 

 underh-ing strata ; but many of the gastropods and some of the other 

 Lyckholm forms are varietally different. The letter following the 

 name of a species refers to the name of the underlying formation in 

 which the species occurs. (See p. 293). 



1 . Cyclocrinites spasski K. 



2. Dittopora colliculata W. 



3. Diplotrypa petropolitana W. 



4. Stomotopora arachnoidea E. Ku. 



5. Plectambonites sericeus W. 



6. Porambonites gigas W. 



7. Rafinesquina deltoidea W. 



8. Strophomena assmussi J. K. W. 



9. Bucania contorta W. 



10. cycloides W. 



11. radiata W. 



12. Isospira bucanoides W, 



13. Murchisonia exilis W. 



14. insignis W. 



15. Pleurotomaria notabilis W. 



16. Sinuites bilobatus W. 



17. Subulites inflatus W. 



> Personal communication. 



