4 BRITISH CARBONIFEROUS BRACHIOPODA. 



enable any but the possessor to understand the shape and character of the object thus 

 treated. It, therefore, required a considerable amount of labour and research before I 

 felt myself at all in a competent condition to endeavour to undertake the publication of the 

 numerous and variable forms which will compose the present monograph. 



Having traced on separate sheets the original figures of all those species said to have 

 been found in Great Britain, and classed these under their respective genera, according to 

 general affinities and resemblances ; my next effort was to procure the loan of the original 

 specimens themselves still extant in the United Kingdom, and which were at once commu- 

 nicated in the most kind and liberal manner by their respective possessors. By this 

 means I have been enabled to class, with a greater or less degree of success, the thousands 

 of specimens forwarded from various quarters around the named and original types of their 

 respective species. 



I have stated this in order that the reader may feel assured that, however faulty 

 and imperfect the present work may appear, no effort has been neglected to ensure 

 as far as possible a correct identification of the species by a direct comparison 

 with the original figured types. In a few cases it has not, however, been possible to 

 procure the originals, such as some of those described by Martin, Portlock, and M'Coy — 

 the specimens being no longer to be found ; but in those comparatively exceptional cases 

 wherein doubt might prevail, I have invariably reproduced not only the author's 

 descriptions but likewise their figures, as in the instance of Spirifera transiens, 

 Sp. mesogonia, Sp. subconica, &c, but without, however, warranting their specific 

 claims. 



After a careful investigation of the various works, I found that considerably more 

 than two hundred species of Carboniferous Brachiopoda were stated to have been 

 found in the United Kingdom, but, as will be hereafter demonstrated, many of these 

 are not British, while others are mere synonyms, or in a great measure attributable to 

 incorrect identifications with Devonian shells, which have been supposed by Professor 

 M'Coy and a few others to be common to both systems. I am very far, however, from 

 wishing to deny that certain forms did continue to live during both the Devonian and 

 Carboniferous periods as well as during the Carboniferous and Permian epochs ; but it 

 would be, I believe, a mistaken notion to suppose that they occurred in that numerical 

 abundance which we should be led to believe from the names introduced into Professor 

 M'Coy's otherwise important work on 'Irish Carboniferous Fossils.' Many of these 

 said to be Devonian shells were identified from undeterminable or obscure fragments or 

 specimens, at times distorted by pressure and cleavage ; and as a large number of them 

 are still extant in Dr. Griffith's collection, Mr. Salter and myself have (through the 

 kindness of their possessor) been enabled to minutely examine and compare a certain 

 number, which invariably turned out to be true Carboniferous and not Devonian types. 

 Thus, for instance, M'Coy's so-termed Sp. simplex belonged to Sp. cuspidala, Sp. speciosa 

 to Sp. laminosa, Athyris concentrica to A. Roissyi, &c. These and other incorrect 



