CARBONIFEROUS AND PERMIAN MONOGRAPHS. 269 



No new British Permian species of Brachiopoda has been discovered since the publi- 

 cation of my monograph, notwithstanding the most zealous researches of several naturalists. 

 The compact Limestone of East Thickley, near Darlington, has been well searched by Messrs. 

 R. T. Manson, T. Parker, and E. Gower, who have succeeded in procuring some excel- 

 lent specimens of several species, such as T. elongata, Cam. crumena, Sp. alata, Strept.pelar- 

 gonatus, Stroph. Goldfussii, St. Morrisiana, Prod, horridus, Discina nitida (D. Koninckii), 

 and Lingula mytiloides or Credneri, so that the total number of Permian species of 

 Brachiopoda occurring in Britain would, according to my views, not exceed sixteen or 

 seventeen species, of which about half would be common to the Carboniferous and 

 Permian periods. 



As far, therefore, as the Brachiopoda are concerned, there exists a very intimate 

 relationship between the Carboniferous and Permian species, and, as Messrs. Kirkby and 

 R. Jones have already shown (and are ready to show still further), that species from other 

 classes partake of the same identity. The Permian strata are, therefore, the natural 

 continuation of the Great Carboniferous period, although it may be desirable to pre- 

 serve the term Permian as originally given by the celebrated authors of ' Russia in 

 Europe and the Ural Mountains Geographically Illustrated ' to those strata which succeed 

 the highest portion of the Carboniferous series. The term " Dyas " recently proposed as 

 a substitute for that of " Permian " appears to me to be a very unfortunate idea, for, 

 besides being incorrect in its meaning, it is, in reality, only a synonym, with which 

 science is, alas, becoming so heavily burdened. 



Strophalosia. 



I am still of opinion that all our known British Permian Slrophalosias should be referred 

 to two species only. 



1. Strophalosia Goldfussii. — Notwithstanding Prof. Geinitz's contrary opinion, 1 I 

 believe that the shells referred to Minister's species in p. 39 of my Permian Mono- 

 graph have been correctly identified, and am also of opinion that what Geinitz terms 

 St. excavata from the Zechstein dolomite of Pdssneck, and the typical St. Goldfussii 

 from the Untere Zechstein of Trebnitz, near Gera, belong to the same species ; but 

 with this difference, that at the last-named place, the shell is found perfect with all its 

 spines, while at Possneck the specimens are either casts, or in a bad state of preservation, 

 and it is in this decorticated condition that the shell is usually found in England. 



2. The second species has been referred to Strophalosia lamellosa of Geinitz ? but I 

 am not so certain that this identification is strictly correct. Prof. Geinitz objects to the 

 idea of uniting King's St. Morrisiana with his St. lamellosa, and considers the two as 



1 ' Dyas oder die Zechsteinforraation und das Rothliegende,' part i, p. 96, 1861. 



