206 bulletin: museum of comparative zoology. 



The question suggests itself as to whether the Kegel may not be of 

 the same age as the Wesenberg, instead of being older as has been 

 supposed. On the basis of the faunas this must be at once answered 

 in the negative, for there are only one or two of the long ranging 

 species which are common to the Jewe and Wesenberg, while there 

 are quite a number of species, particularly trilobites and brachiopods, 

 common to the Jewe and Kegel. 



The presence of a few of the Wesenberg trilobites at localities south 

 of the outcrop of the Wassalem suggests that there may be a thin edge 

 of the Wesenberg in that region, probably overlying the strata with 

 the Cyclocrinites, but I did not have time to search for outcrops which 

 might have shown such relations. It seems more probable, however, 

 that these trilobites are not restricted to the Wesenberg horizon, 

 but are found in the Kegel as well. 



It seems very possible therefore, that the Lyckholm rests at the 

 west on the Kegel and further east upon the Wesenberg, and there is 

 undoubtedly an unconformity at the base of the Lyckholm, for there 

 is at most, only a very small fraction of the normal thickness of the 

 Wesenberg present south of Wassalem. The relations of the forma- 

 tions may be as represented on Plate 3. 



THE LOWER AND MIDDLE ORDOVICIAN OF SWEDEN. 



To make a direct correlation between the various subdivisions of 

 the Ordovician in Russia and North America is impossible, the testi- 

 mony of the few species common to the two areas being entirely out- 

 weighed by the general unlikeness of the faunas. It was a realization 

 of this fact which caused a visit to Sweden and Norway after studying 

 the Russian sections. I visited the rather complete and easily ac- 

 cessible section at Kinnekulle, and other sections in Viistergotland at 

 Hunneberg, Ekedalen, and Alleberg near Falkoping. In Ostergot- 

 land I collected at the large quarries at Borghamm and at the old 

 quarry at Vastana, the Husbyfjol of the literature on trilobites, and 

 visited a number of very poor localities in the vicinity of Motala. In 

 Scania I had the very kind guidance and assistance of Professor Dr. 

 J. C. Moberg, without whose help it would have been impossible for 

 me to have understood the very imperfectly exposed sections on the 

 Fagelsang and at Jerrestad. I was not able to visit Oeland on account 



