SUPPLEMENT 



BRITISH DEVONIAN BRACHIOPODA. 



The first, part of my Devonian Monograph was published in August, 1864; the 

 second in June, 1865. 



On account of the comparatively limited area occupied by the fossiliferous Devonian 

 Formation in Great Britain, the few collections, and the difficulty of procuring well- 

 preserved specimens of a large proportion of the species, that Monograph caused me 

 more trouble than those relating to the other divisions of the Palaeozoic period. 



Every specimen that could be procured was carefully examined, and the whole illus- 

 trated in twenty quarto plates; but it was to be expected that further collecting and research 

 by local geologists would, with time, bring to light new facts in connection with those 

 species already discovered, and that a small number of additional forms, not recorded in 

 my work, Avould be the result of further investigation. This expectation has been realised, 

 as will be seen in the sequel; and I have also been able to correct several, at the time 

 unavoidable, mistakes, revise to some extent the old Monograph, and add to the number 

 of our British Devonian species. Much will remain to be achieved by further favorable 

 conditions. Upon the Continent and in America the Devonian rocks and fossils have 

 been carefully studied by competent geologists and palaeontologists, and this has also 

 assisted us in correlating our divisions with those established upon the Continent, and in 

 arriving at a more correct identification of some of our own species by comparing them 

 with foreign types. 



At page 157 of his ' Anniversary Address,' as President of the Geological Society,^ 

 Mr. Etheridge, referring to the Devonian Brachiopoda, says, " With the exception of the 

 Pishes of the Old Red Sandstone (125 species), this is the largest group in the British 

 Devonian rocks. We should expect this when we know that no less than 61 genera and 

 over 1100 foreign species have passed through the hands of European, American, and 

 British zoologists and palaeontologists, and all have been described; of these 1100 species 

 only 116 are British ; and of the 61 known genera we possess 26." 



1 'Quarterly Journal of the Geological Society,' vol. xxxvii, 1881. 



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