338 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The most diagnostic fossil in the Tamsal formation is Pentamerus 
borealis. In the Kristiana region, this is confined to the upper portion 
of Kiaer’s zone 6c and to 7a, that is, to the uppermost zone of the 
Norwegian Lower Llandovery and the lowest zone of the Upper 
Llandovery, where it is associated in the latter zone with Bilobites 
bilobus, and in the former with Plectambonites quinquecostata McCoy 
(probably a different species since McCoy’s form came from the 
Ordovician), Coelospira hemispherica, Stricklandinia lens Sowerby, 
and Camarotoechia decemplicata (Sowerby); all of which in the same 
or closely identical species make their first appearance in the upper- 
most zone of the Gun River formation, and this fact points to the 
probability that this zone, and probably some parts of the preceding 
zones, represent the Tamsal formation in the Anticosti section. If 
this view be correct, it follows that the equivalent of the Becsie River 
formation is not present in the Russian Silurian of the Baltic, and 
hence there is a considerable time break between the Borkholm and 
Jorden beds. It is worthy of note that the faunal break at this point 
is far greater than that between the Lyckholm and Wesenberg. 
From one locality a small collection was made which in the field 
reminded me of the Cataract fauna, but until this collection has been 
studied and compared it is thought best to place no emphasis upon it. 
At any rate, it would not depreciate the correlation just made. 
The St. Johannis formation is almost certainly the equivalent of 
the Wenlock of Scandinavia, England, and west Europe generally, 
and the Rochester and Niagara of North America. With the Wen- 
lock of Norway, Kiaer’s zones 8a to 8d, the formation has at least 
twenty-eight species in common, of which the more diagnostic are 
Paleocyclus porpita, Thecia swindernana, Camarotoechia borealis, 
Cyrtia exporrecta, Dalmanella elegantula, Dinorthis rustica, Eospirifer 
radiatus, Meristina tumida, Rhipidomella hybrida, Rhynchotreta cuneata, 
Spirifer crispus, Wilsonia wilsont, Omphalotrochus discors, Calymene 
tuberculata, Encrinurus punctatus, and Bumastus barriensis. Corre- 
lation of the St. Johannis formation is therefore made with stage 8 
(Wenlock) of the Norwegian sections. Since many of the fossils to 
which reference has been made in this paragraph also occur in the 
lower zones of Kiaer’s stage 9 (Lower Ludlow) it is possible that the 
upper portion of the St. Johannis formation may find an equivalence 
in the lower portion of stage 9. 
With the English Wenlock or Salopian series, the St. Johannis 
formation has nearly the same species in common as it has with the 
Norwegian section as well as some additional species and the correla- 
