148 



BRITISH SILURIAN BRACHIOPODA. 



obtained. M. de Verneuil describes it from black Devonian (?) limestone at Ustkataf, 

 between Jurjusensk and Simsk, in the south of the Ural Momitains, and from Bogoslofsk, 

 in the South Urals. M. Barrande found it in the Upper Silurian rocks of Bohemia ; and 

 Prof. Hall states, at p. 259 of vol. iii of his 'Palaeontology of New York,' that "this 



Ketley has drawn up the following Table as a guide, which, although not quite complete, is here 

 reproduced, as it illustrates a subject upon which further careful observations should be^made : 



Brachiopoda. 



Wenloch Limestone, Upper Shale, Lower Ludlow of 

 Dudley. Dudley. the Ludlow District. 



Atliyris tumida 



Atrypa reticularis 



Retzia cuneata 



Spirifer crispus 



— plicatellus 



— — var. interlineatus 



— trapezoidalis 



Pentamerus galeatus 



Rhynchonella deflexa 



— Lewisii 



— nucula 



— Wilsoni 



Leptsena transversalis 



Orthis biloba 



— elegantula 



— — var. obicularis 



— hybrida 



Strophomena depressa 



— euglypha 



— filosa 



— funiculata 



Chonetes laevigata 



— minima 



Discina Forbesii 



— striata — ,, — 



— rugata „ „ — 



Lingula Symondsii — „ „ 



— Lewisii — „ — 



Obolus Davidsoni „ „ — 



— transversus — „ — 



At p. 430 of vol. iii of the 'Geological Magazine' (Sept., 186G), Dr. Holl observes that the above- 

 mentioned Upper Wenlock Shales, notwithstanding the Wenlock aspect of their fauna, are considered, 

 on good authority, to belong to the base of the Ludlow series. Mr. Salter refers the student to Sir R. 

 Murchisou's often repeated statement, that the Lower Ludlow seems but to be an Upper Wenlock Shale ; 

 where the former is represented by mud-stone the fossils are like those of the Wenlock. The Brachiopods 

 have a greater range than the other slicUs. 



