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RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 213 
Niobe laeviceps, and Nileus armadillo are found in these strata. The 
Asaphus limestone contains the typical species, Asaphus expansus, 
Lycophoria nucella, etc., and it may be noted that the Lower Linsen- 
schicht is developed in this district. The Gigas and Platyurus lime- 
stones have many cephalopods, but few trilobites. Both the Chiron 
and Ancistroceras limestones contain their typical fossils and are 
followed by fifteen meters of limestone containing Chasmops odini, 
Echinosphaerites aurantium, and Oxoplecia dorsata. 
The Macrourus limestone contains Chasmops maxima Schmidt. 
The black Trinucleus shale contains Trinucleus seticornis, Calymene 
trinucleina Linrs., Remopleurides radians Barr., Dalmanella argentea 
His., and the graptolites Dicellograptus anceps, Diplograptus pristis, 
D. truncatus, and Lasiograptus margaritatus. The gray limestone is 
reported as containing numerous fossils, which however, occur only 
as fragments, and I have seen no list. 
The red Trinucleus shale contains few fossils. Remopleurides dor- 
sospinifer, Proetus brevifrons, Agnostus trinodus, Trinucleus, and Pseu- 
dosphaerexochus laticeps have been reported. The Leptaena limestone 
contains a very large fauna, comparable to that of the Lyckholm 
and Borkholm. There has been a great deal of discussion about 
the relative positions of the Leptaena limestone and Trinucleus shale 
in Dalecarlia. Although their faunas are quite different, yet both are 
characterized by an influx of Bohemian species, and both show the 
beginnings of a fauna like the Silurian. Furthermore, the presence 
of Dicellograptus anceps and D. complanatus are indicative of the 
youngest Ordovician age of the Trinucleus shales. The Leptaena 
limestone seems to show the physical characteristics of a “reef,” 
though not perhaps of a coral reef, as Nathorst has suggested. 
VASTERGOTLAND. 
The strata of the third belt are best exposed in Vastergétland where 
the Cambrian, Ordovician, and Silurian rocks are practically hori- 
zontal and well shown on the sides of small “mountains” in which 
they have been protected from erosion by a capping sheet of diabase. 
On account of its quarries, Kinnekulle presents unusual opportunities 
for studying the Orthoceras limestone and the section there is one of 
the classic ones in Swedish geology. Throughout this region the 
Ordovician rests upon Upper Cambrian formations, and the Dictyo- 
nema shales are usually either very feebly developed or entirely 
