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BRITISH CARBONIFEROUS BRACHIOPODA. 



(1. Camarophoria erumena, Martin. 



2. — globularis, Phillips. 



3. — (?) laticliva, M'Coy. 



4. — isorhyncba, M'Coy. 



(1. Rliynchonella or Camarophoria (?) proava, Phillips. 

 2. — semisulcata, M'Coy. 



3. — gregaria, M'Coy. 



4. — nana, M'Coy. 



So that out of upwards of thirty so-termed species recorded by various palaeontologists, 

 or geologists, as having been found in the Carboniferous rocks of Great Britain, but seven 

 of Rhynchonella, and three or four of Camarophoria, appear to me as worthy of being 

 retained ; all the others, with the exception of three or four still doubtful forms, are either 

 synonyms or names of species that have not in reality been hitherto discovered in Great 

 Britain. The extent of variations in shape and even character assumed by certain species 

 is quite perplexing; for instance, Rh. acuminata is at times entirely smooth, or is covered 

 more or less with ribs ; sometimes it is a heart-shaped shell, while at other times it is 

 completely depressed and almost flattened ; still, every passage connecting these extreme 

 cases can be easily recognised, and it should warn the palaeontologist of the necessity of 

 founding his appreciations, not from the study of one or two specimens only, but from the 

 inspection of a large series of its varieties. 



Notwithstanding all the care and trouble I have taken in the endeavour to determine 

 as correctly as possible the limits of the various species, I cannot pretend to have always 

 succeeded, and would strenuously advise the reader to study the matter independently, 

 and not to blindly adopt the views here recorded, as certain of them may eventually prove 

 erroneous. 



In order to facilitate research, I have carefully selected and represented all the more 

 important variations assumed by each species, as I have always considered the illustration 

 of a typical form only, to be insufficient as it does not generally convey to the mind 

 the true average characters of the species (if I may be permitted the use of such an 

 expression). 



Rhynchonella reniformis, Sowerby. PI. XIX, figs. 1 — 7. 



Terebratula reniformts, Sowerby. Min. Con., pi. ccccxcvi, figs. 1 — 4, Sept. 1825. 



— — Phillips. Geology of Yorkshire, vol. ii, p. 222, pi. xii, figs. 



13—15, 1836. 



Hemitiiyris — M'Coy. British Palaeozoic Fossils, p. 441, 1855. 



11 ii ync HON ella — Morris. A Catalogue of British Fossils, p. 146. 1854. 



Spec. Char. Transversely reuiform, wider than long; dorsal valve more or less 



