—E—— SS SS CULL Cl 
TWENHOFEL: EXPEDITION TO THE BALTIC PROVINCES. 305 
and Ptilodictya flabellata from the same locality is referred by Bassler 
to the Borkholm. 
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 Lyckholm is of Richmond 
age, as stated in his work, but that the Lower Lyckholm 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 Lyckholm and 
underlying 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. 
zi, radiata W. 
12. Isospira bucanoides ~ W. 
13. Murchisonia exilis W. 
14. insignis ee 
15. Pleurotomaria notabilis W. 
16. Sinuites bilobatus W. 
17. Subulites inflatus W. 
1 Personal communication. 
