668 PROCEEBINGS OP THE GEOIOGICAI SOCIETY. 



peculiar species of Clymenia and Goniatates (55 in all) constitute 

 an assemblage of organic remains not known in the Carboniferous 

 series anywhere. 



5. BracTiiopoda. — We cannot pass over this important class of 

 MoUusca, which plays so important a part in the fauna of the 

 marine Devonian rocks ; and although in this group there is more 

 community with the fossils of the Carboniferous series than any 

 other, still it will be shown that it is chiefly through the Upper 

 Devonian and passage-beds that the affinity exists. I restrict the 

 term '^ Upper Devonian" to those beds that repose upon the highest 

 member of the Upper Old Eed Sandstone at Vention, George Ham, 

 Marwood, High Bray, Dulverton, and Wiveliscombe — in other words, 

 to that latitude occupied by the uppermost beds of the non-fossili- 

 ferous red sandstone that stretch from Morte Bay to Wiveliscombe. 

 The labours of Mr. Davidson *, in his elaborate monographs upon 

 the Devonian and Carboniferous Brachiopoda, have now determined 

 and fixed the specific nomenclature of this class with such precision 

 that we are enabled, through his valuble researches, to correctly 

 estimate their numerical and specific values, as well as to collate 

 them with the continental Devonian species. We find that twenty- 

 five genera and ninety-nine species are known in the British 

 Devonian rocks, and that thirteen of these are common to them 

 and the Carboniferous in Britain or Ireland.' Seven of these 

 thirteen do not occur below the Upper Devonian — viz. Atliyris oh- 

 longa, Discina niticla, Lingula squamiformis, Productus scabricidus, 

 Kliynchonella acuminata, Spirifera Urei, and Terebratula saccuJus ; 

 whereas the remaining 6 species, BTiynchonella pleurodon, JR. pug- 

 nus, R. reniformis, Spiriferina insculpta, Streptorhynchus crenistria, 

 BtropTiomena rliomhoidalis, and Terebratula sacculus are common to 

 both the Middle Devonian and Carboniferous, one species only, the 

 doubtful Ghonetes Hardrensis, being common to the Lower, Upper, 

 and Carboniferous. The remaining eighty-six species are therefore 

 strictly Devonian forms. {Vide Table II. p. 616.) Considerable 

 weight must be attached to those genera which here as well as in 

 continental Europe are not known above the Middle group, and 

 equally characterize it both in our own two areas (viz. North and 

 South Devon) and in those of the continent. The following eight 

 genera and nine species are here given to show their value and 

 relation : — 



Calceola sandalina t. 

 Davidsonia Verneuilii, 

 Merista plebeia. 

 Pentamerus biplicatus. 

 „ brevirostris. 



Rensseleria stringiceps. 

 Retzia ferrita. 

 Stringocephakis Burtini. 

 Uncites gryphus. 



Of the ninety-nine British s-peGies,Jlfty-two are represented in either 

 the Rhenish, Belgian, or French areas, only six of which are known 

 in, or are common to, the Carboniferous rocks. In Table YIII. p. 658, 

 is shown the relation of our Devonian species to those of the three areas 



* Monog. Brit. Der. Brachiopoda, Pal. Soc. 1864-66. 



t This form has not yet been satisfactorily determined in North Devon. 



