612 A. W. GRABAU — LOWER ORDOVICIC FORMATIONS 



profound knowledge of the region made him the leading authority in this 

 field, and I wish to record here his zeal and eagerness in guiding us, so 

 that we should miss none of the important localities of the district. His 

 untimely death is a hard blow to Swedish science and is regretted in 

 America as well as in his native land. In the following descriptions 1 

 follow him closely, with only occasional additions of my own; for the 

 interpretations, however, I alone am responsible. 



East Scania.— The eastern region is shown especially well in the sec- 

 tions between Tommarp and Jerrestadt, the latter lying about 3 kilo- 

 meters east of the former. Some of the best exposures arc found along 

 the creek passing through the two localities, but only in the more westerly 

 area (Tommarp) are the exposures continuous. In the Jerrestadt region 

 we found only scattered exposures, and some of the beds we conld study 

 only after removing the surface soil. Professor Moberg's intimate knowl- 

 edge of the region here stood us in good stead, but we were not certain 

 that the succession might not be interfered with by unrecognized faults, 

 in which this entire region abounds. At Tommarp, however, the succes- 

 sion was clear and faults were eliminated. 



The Dictyonema shales are shown in the exposure near Jerrestadt at 

 several places and appear to lie directly on the Acerocare beds of the 

 Upper Cambric, though the contact is not shown, in the lower beds 

 Dictyonema flahelli forme Eichw. occurs, and higher up Clonograptiis 

 tenellus var. callavei Lapw. and var. liians Mbg., as well as Bryograptus 

 Ihunnebergensis Mbg., while in the highest part occurs the subzone with 

 D. flabelliforme var. nonvegica Kjerulf and Bryograptus kjerulfi Lpw. 

 These beds are succeeded by alum shales carrying Ceratiocaris scanicus 

 Westergard, and believed to be the equivalent of the Shumarclia zone of 

 the Ceratopyge shales, while the limestone immediately succeeding them 

 is classed by Moberg as Ceratopyge limestone, though typical fossils have 

 not been found in it. Above this follow the Lower Didymograptus shales, 

 the zone with Didymograptus balticus, D. geometricus Tornq., D. con- 

 striclus Hall, Tetragr. quadribrachiatus, and Schizograptus rotans Tornq., 

 following directly on the supposed Ceratopyge limestone. Then follow 

 Tornquist's zones c with Phyllograplus clensus Tornq. (= P. angusti- 

 folius Hall) and d with Isograptus gibberrulus JSTich. {Didymograptus 

 caduceus). All of these represent Lower Arenig. They are succeeded 

 by Orthoceras limestone, apparently representing the Megalaspis limbala 

 beds, but this is not definitely ascertained. Somewhat higher, after a 

 covered interval, occur shales with Dicranograptus clingani Can-., C. 

 bico?*nis IIn\], Diplograptus quadnmucronatus var. spiniger Lapw., Lasio- 

 graptus margarilatus Lapw., and Corynoides calicularis Nich. Higher 



