Ch. XXVI.] 



UPPER AND MIDDLE DEVONIAN. 



421 



ionsti- 



Fiff. 551. 



ica.* I shall proceed first to treat of the main divisions which have been 

 established in Europe. 



Upper Devonian Rocks. 

 The slates and sandstones of Barnstaple (No. 1, a, 6 of the preceding 

 section) are represented in Cornwall by the limestones and slates of Pether- 

 wyn, which rise in like manner from under the Culm Measures, 

 tuting the Petherwyn group of Prof. 

 Sedo-wick. These beds contain the 

 very common Spirifer disjunctus, 

 Sow. (/S. Verneuilii, Murch.), (see 

 fig. 551), a species distributed over 

 the whole of Europe, and found even 

 in Asia Minor and China. Among 

 many other fossils the Clymenia 

 linearis (fig. 552) and the minute 

 crustacean Cijpridina serrato-striata (fig. 553) are so characteristic of 

 these upper beds in Belgium, the Rhenish Provinces, the Hartz, Saxony, 



Fig. 552. 



^^~ 



nrifer disjunctu% Sow 



neuilii. Murch. 

 Upper Devonian, BouIufeC^e. 



Syn. Sp. Ver- 



Cypridina serrato-striata. Sar.dberger. 

 ^yeilburg, &c. ; Nassau ; Saxony ; Bel- 

 gium. 



Clymenia linearis, MUnster. 

 Pether^?ya, Cornwall ; Elbersreuth, Bavaria. 



and Silesia, that strata of this division in Germany are distinguished by 

 the names of " Clymenien-Kalk," and " Cypridinen-schiefer."f 



With these are many Goniatites [G. subsulcatus, Miinster, and other 

 species) both in England and on the continent. In Germany they are 

 usually confined to distinct beds, as at Oberscheld, also at Couvin in 

 Belgium, &c. Trilobites are not unfrequent in Cornwall and North 

 Devon ; they are chiefly restricted to species of Phacops (for genus, see 

 fig. 585) ; but in the upper Devonian hmestones of the Fichtelgebirge, as 

 at Elbeisreuth in Bavaria, there are numerous genera and species which 

 never rise higher in the series or appear in any portion of the carbonifer- 

 ous limestone. 



Middle Devonian 



The unfossiliferous series (No. 2, p. 420) of North Devon, and the calca- 

 reous beds of Ilfracombe (3), correspond to the Dartmouth and Plymouth 



* See Dr. Fridolia Sandberger on the Devonian rocks of Nassau (Geol, Verlialt, 

 Nassau) ; Fried. A. Roemer, on the Hartz Devonian Rocks, in Dunker and Von 

 Meyer's Palseontographica, 3d vol. pt. 1. 



f See Murchisou's Siluria, chapters x. xiv. and xv. 



