ETHERIDGE DEVONIAN KOCKS AND FOSSILS. 635 



stand thus: — Plantte 12 species, Annelida 1 sp., Crustacea 20 sp., 

 Polyzoa 1, Pisces 113 ; whereas the Marine Devonian contains 12 

 classes, 125 genera, and 3S3 species, distributed through its Lower, 

 Middle, and Upper members in the West Somerset, Xorth and South 

 Devonian, and Cornish areas, or in the typical Devonian region. AVith 

 these Devonian species are compared those occumug in the Carbo- 

 niferous Slate of Ireland, many of which pass from the Upper Devo- 

 nian group beneath into the Carboniferous series, which in the Xorth- 

 Devon area reposes upon the Upper Devonian rocks at Barnstaple, 

 and in the country to the south. The whole Devonian fauna is also 

 compared with the Carboniferous generally ; and, to make my com- 

 parisons stiU more important and complete, I have endeavoured to 

 compare the Enghsh types of the Devonian species and those of the 

 Irish Carboniferous slate with those in the groups of rocks recognized 

 as Lower, Middle, and Upper Devonian in the Ehenish provinces, 

 Belgium and France (the Bas Boulonnais) ; by this means I have 

 arrived at some data as to the distribution of the Devonian species in 

 space and time, and their true relation to the Old Pted Sandstone on the 

 one hand, and the succeeding Carboniferous group above on the other ; 

 it serves to show us also that the marine Devonian system, as a 

 whole, stands alone, through its organic remains — 5 species only being 

 common to the Old Pved Sandstone and Devonian, out of the 149 

 species known in the former, and 385 in the latter. Three of these 

 are Plants, and the remaining two Pish ; the 113 species of fish, 

 therefore, are almost the only witnesses of animal life in the vast 

 thickness of the Old Pied Sandstone. As we have, therefore, no 

 standard by which to compare the Devonian, or the Carboniferous, 

 except through the '•' Devonian," there is no alternative but to 

 accept the British species as types and data for comparison with 

 the continental Devonian series and the Carboniferous ; and admit- 

 ting, upon stratigraphical evidence, that the Devonian is beneath 

 the Carboniferous everywhere in England and Europe where they 

 have been examined, it of necessity follows that the species distri- 

 buted through the Devonian rocks preceded the Carboniferous in 

 time, and also that the few species that occur in both are, without 

 exception, of Devonian types, occurring either in the British area, or 

 in one or more of the three European areas named; and this strati- 

 graphical position and Hfe-succession are clearly shown in jS'orth and 

 South Devon and West Somerset. (See Table II., p. 616, and Table 

 lY., p. 640). 



I purpose comparing the British species occupying the two De- 

 vonian areas amongst themselves, and then entering upon their 

 comparison with relation to their foreign equivalents in the Rhe- 

 nish provinces, Belgium, and Prance, and finally comparing them with 

 the succeeding Carboniferous series in this country and in Ireland. 



2. Lower Devonian species of West Somerset and J^orth Devon. — 

 These lower gritty slates and associated bands of limestone contain a 

 fauna almost peculiar to themselves ; and it is remarkble how many 

 of the known species are common to Xorth Devon and the Rhenish 

 and Belgian areas, notwithstanding that they are so widely separated; 



