RAYMOND: CORRELATION OF THE ORDOVICL\N STRATA. 213 



Niohe laeviceps, and N ileus armadillo are found in these strata. The 

 Asaphus Umestone contains the typical species, Asaphus expatisus, 

 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 oditii, 

 Echinosphacrites aurantium, and O.voplecia dorsaia. 



The Macrourus limestone contains Chasmops maxima Schmidt. 



The black Trinucleus shale contains Trinuclcus sdicornis, Cahjmene 

 trinudcina Linrs., Rcmopleiirides radians Barr., Dalmanella argentea 

 His., and the graptolites Diccllograptus anceps, Diplograptus pristis, 

 D. fruncatus, 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 Diccllograptus 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. 



Vastergotlaxd. 



The strata of the third belt are best exposed in Vastergotland 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 



