i 
RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 195 
ate showing that it was formed at or near the shore, and at a time 
immediately subsequent to a period of erosion. 
The Kunda formation has a somewhat irregular thickness, being 
thickest in the east and very thin at the west. On the Walchow it is 
thirty-two feet according to Lamansky, at Papowka it is thirty-four 
feet with the top not seen, at Ontika eighteen and one half feet, at 
Asserien fourteen and two thirds feet, at Kunda fifteen feet, at Reval 
four feet, and three and one half feet at Packerort. The abundant 
fauna at Reval is practically the same as that at Kunda, but as the 
fauna seemed to be the same all through the section at Kunda, this in 
itself would not indicate whether the thinness at Reval was due to 
erosion at the top of the formation or to a smaller original deposition. 
Schmidt states that west of Reval the Orthoceras limestone passes 
into a sandstone, but I myself saw no evidence of this, either at Baltish- 
port or on the Island Rogo. At these localities the formation consists 
of a rather thick-bedded hard limestone without many fossils, and at 
the base is a conglomerate made up of pebbles of green glauconitic 
limestone and irregular pieces of dark shale, these latter proving on 
analysis by Kupffer to contain, in some cases, a large percentage of 
phosphoric acid. 
The fauna of the Kunda formation is dominated by Mollusca, 
mostly cephalopods and gastropods. Pelecypods are rare, making 
here their first appearance in the Russian section. Typical fossils 
are Vaginoceras vaginatum, V. commune, Maclurites helix, Estonio- 
ceras lamellosum, Asaphus raniceps, Pliomera fischeri, Lycophoria 
nucella, and Pterygometopus sclerops. 
WIERLAND GRouP. Cl, 2 and 3, and part of D, (Echinosphaerites 
limestone, Kuckers schicht, Itfer schicht, and basal portion of the 
Jewe schicht), of Schmidt. 
As already noted, Schmidt gave geographic names to all the strata 
above the “Glint,” but these names are of very unequal value, some 
of them designating true formations, and others indicating merely 
the quarry at which a certain fauna or type of strata was seen. The 
faunas of all three of the formations named above are very closely knit 
together by the presence of Echinosphaerites aurantium and species of 
Chasmops. The name Wierland which I have applied to the group 
is that of the district in which most of the localities for Kuckers and 
Itfer are located, and in which the lower divisions are well developed. 
The lower members are also given geographic names to correspond to 
the two upper members named by Schmidt. There is really a greater 
faunal change between the Reval and Dubowiki members than be- 
tween any other two in the group. 
