( 564 ) 



as siR-li. As far as 1 can see this species of Hyolithus, wlieii lluliii 

 described it, had not l)een discoA^ered in company with a fossil from 

 which its age miglit he determined. Moberg ^) afterward fonnd many 

 specimens in a few big lilocks of sandstone, wliicli furnished him 

 the material for the description of the new species of Trilobites called 

 Holmia Lundgreni. The latter lay in the neighbourhood oflakeTun- 

 byholm in the eastern })art of the province of Schonen; according 

 to MouKRG suchlike stone with remains of Trilobites occurs as firm 

 rock not far from this place. As Moberg informs us that sandstone 

 with Holmia Lundgreni is ohler than lliat witli Holmia KjerultiLinrs, 

 this was })robably also tlie case with the sandstone-layers of which 

 the Murmerwoude erratic-blocks formerly formed part. 



It appears from ]\Iorerg's description of the stone of the erratic- 

 blocks with Holmia Lundgreni, that this stone in some respects 

 resembles the material of which the Murmei'woude eri-atic-blocks 

 consist. Both are very fine-grained and contain no calcium-carbonate. 

 There does not seem to be much dilference in colour either, at least 

 as far as some parts of the Swedish erratic-blocks are concerned: 

 MoBERG tells us that the sandstone descril)ed l)v him is chiefly of a 

 bright light-grey colour, though sometimes showing small brown 

 spots of ferrihydroxide. My erratic blocks, however, contain no pieces 

 of phosphorite, which those from the neighl)Ourhood of lake Tunby- 

 holm do. 



Besides the erractic-blocks spoken of just now, others of sandstone 

 Avith Hyolithus de Geeri-remains were also found, as Holm tells us, 

 in the province of Schonen, near Simrishanm and Köpinge. 



The same author makes mention of suchlike stones having been 

 gathered near Rüdersdorf not far from Berlin, and near Biitzow in 

 Mecklenlnu'g. It follows from the descri})tions he gives of these 

 pieces, that petrographically they bear no resemblance to those found 

 at Murmerwoude. The latter are least different from the erratic-block 

 found by Prof, de Geer at Hüdersdorf. IMy pieces, ho^^'e^•er, contain 

 no particles of glimmer. 



No more ha\'e corresponding erratic-blocks of Hyolithus-sandstone 

 been found in any part of the Netherlands. The first of this kind of 

 stone were made mention of by van Calker"^). They originate from 

 Steenbergen in the northern part of Drente; they are three stones 



^) MoBERG. Sveriges alsta kanda Trilobiter. Geo!. Foren, in Stockholm för- 

 handlingar 1899. Bd. 21. Haft 4. p. 324. 



2) Van Galker. Ueber ein Vorkommen von Kantengeschieben mid von Hyoli- 

 thus- und Scolithus-Sandstein in Holland. Zeitschr. d. Deutsch. geol. Gesellschai't. 

 Jahrg. 1890. p. 581. 



