Correlation of the Meadfoot and Siegenian Beds. 169 
Cultrijugatus Beds and the Meadfoot Group with the Emsian and 
Siegenian. I am unable to find any evidence in favour of this 
parallelism in the detailed studies of Mr. W. A. E. Ussher on the 
Devonshire rocks. On the contrary, it seems foolish to correlate 
the whole of the Staddon Grits with the Cultrijugatus Beds, when 
certain bands of the former have yielded Z'ropidoleptus rhenanus. 
Sect. 5. 
Finally, a few words may be said about the Devonian rocks of 
North Devon. The stratigraphical succession is less known than 
in the South; nevertheless, it seems very doubtful if it will ever be 
possible to distinguish the three horizons of the Siegenian in the 
Lynton Beds which correspond to the Meadfoot Beds, according to 
Ussher! and Evans.2 In fact, the Devonian of North Devon, 
where the quartzoschistose facies characterizes not only the Lower 
Devonian but affects also the Lower Middle Devonian (Couvinian) 
and even the lowest beds of the Givetian, would have to be compared 
with the Northern border of the ‘‘ Bassin de Dinant”’ or with the 
“Massif de la Vesdre”. In the latter region the Devonian rocks 
below the Givetian Limestone consist of an alternation of purple- 
red shales and greenish arenaceous bands; conglomerates occur at 
several horizons.3 More especially the Siegenian consists mm the 
upper part of purple-red shales and greywacke with pink sandstones, 
and in the lower part of grey and bluish sandstones and quartzites 
with dark-blue slates. Haliserites Decheslianus and bone-beds of 
Ostracoderms (Pteraspis) are frequent in the Taunusian or Lower 
Siegenian.4 In the same way the Lynton Beds of Devon contain 
beds with Pteraspis. In the present state of our knowledge, how- 
ever, it is not possible to establish a more detailed correlation between 
the Lower Devonian of North Devon and the Ardennes. 
Sect. 6. 
In 1912 I showed that the Siegenian presents the same succession 
in the South of the Ardennes—southern border of the Bassin de 
Dinant, Anticlinal de Bastogne, Bassin de Houffalize, Bassin de 
Eifel, Anticlinal de Givonne—and in the Siegerland. It may now 
be concluded that a similar succession occurs also in Cornwall and 
South Devonshire. 
[Note : In accordance with modern usage Dr. Asselberghs adopts 
Siegenian and Emsian in place of the much misused term 
Coblentzian. The necessity for discarding the latter is shown by 
Maillieux, Bull. Scc. belge de Géol., vol. xxx, 1920.—L. D. Stamp.] 
1 Ussher, ‘“‘ Geology in the Field’’: Jubilee Vol. Geol. Assoc., 1910, pp. 864, 
et seq. ; 
2 Evans, Grou. Maa., 1919, pp. 547-9. 
3 A section through the Massif de la Vesdre has been given recently in the 
Bull. Soc. belge de Géol., vol. xxix, 1919, pp. 220-31. 
4 Asselberghs,‘‘Découverte de bone-beds & Ostracodermes dans le Taunusien, 
a lest dela Meuse’’: Bull. Sce. belge de Géol., vol. xxx, 1920. 
