HISTORY OF RESEARCH. 



cvn 



as those in the Birkhill and Gala beds of South Scotland in the same order of 

 sequence, and parallel them with those of many other districts, British and 



Foreign. 



In the following year Marr gave a revised list of the 

 Frankenwald and Thuringerwald Graptolites preserved in 

 the Dresden Museum. This list is of special interest, as 

 many of these forms are the originals of the figures on 

 the plates of Geinitz's work, 'Die Graptolithen,' 1852. 

 Marr also made known the presence of Graptolites in the 

 representatives of the Wenlock formation in Thiiringia and 

 the neighbouring parts of Bavaria. 



1889. 



Marr, 



" Notes ou the Lower 



Palaeozoic Rocks of the 



Fichtelgebirge," ' Geol. 



Mag.,' dec. 3, vol. vi. 



1889. 



De Rouville, 



" Note sur un nouvel 



Horizon de Graptolites 



dans le Silurien de 



Cabrieres," ' Bull. Soc. 



Geol. de Prance,' 



t. xviii. 



De Rouville made known the presence of Graptolites in a 

 rich Arenig fauna discovered near Cabrieres. No specific 

 names of Graptolites are given. 



The same year Lap worth, after pointing out the systematic 

 importance of the existence of a typical Arenig fauna in the 

 Ballantrae Rocks of South Scotland, the discovery of which 

 had been made known by him in 1886 (Jukes-Browne, ' His- 

 torical Geology,' 1st Edition), gave a generalised account of 

 his conclusions respecting the structure and sequence through- 

 out the Southern Uplands, and paralleled in tabulated form 

 their graptolite bearing formations with their equivalents in 

 England and Wales. 



A paper on the fauna of the Graptolithengestein of the 

 German Drift erratics, with special relation to their Grapto- 

 lites, was published by Jaekel in 1889 (compare the subse- 

 quent memoir by Jahn). 



Several Graptolite species are described and figured, and 

 it is proposed to divide the genus Monograptus into two new 

 groups or genera — Pristiograptus and Pomatograptus, a 

 similar division being regarded as probably equally applicable 

 to the two- and many-rowed forms of Graptolites. 



Pristiograptus is characterised by a straight or convexly 

 curved polypary, cylindrical cells in contact throughout, having their apertures 

 occupying the whole of the upper end of the cell, and their apertural processes, 

 if present, occurring as spines on the lower edge of the aperture. 



1889. 



Ltqnvorth, 



" On the Ballantree 



Eocks of S. Scotland 



and their place in the 



Upland Sequence," 



' Geol. Mag.,' dec. 3, 



vol. vi. 



1889. 



Jaekel, 



" TJeber das Alter des 



sogennanten Grapto- 



lithengesteins mit 



besonderer Beriick- 



sichtigung der in dem- 



selben enthaltenen 



Graptolithen," 



' Zeitschr. deutsch. geol. 



Gesell.,' bd. xli. 



