674 



PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



the Gasteropoda, which have been carefully compared. Twelve 

 genera and forty-six species occur in the Devonian ; and of these 

 also five genera and seven species pass to the Carboniferous, viz. Acro- 

 culia vetusta, Euomphalus planorhis, Looconema rugifera^ L. tumida, 

 MurcMsonia angulata, M. spinosa, and Pleurotomaria expansa. Three 

 or four of these I much doubt, but I give them as they are recorded 

 by Prof. Phillips, although a comparison with his figures and de- 

 scriptions causes me to interrogate them. 



Much could be said relative to the Echinodermata. I, however, 

 feel confident that great confusion exists respecting the whole of the 

 Devonian species, and especially so with relation to those said 

 to be common to the Carboniferous and the Lower and Middle 

 Devonian ; their badly preserved condition, usually only in a frag- 

 mentary state, scarcely justifies us in relying upon them as being of 

 specific value. 



7. List of Species common to the Devonian and Carboniferous for- 

 motions. — Table X. is constructed to show at once the relation 

 between those species said to be common to the Carboniferous and 

 Devonian rocks, in which every 'known recognized form is given, and 

 arranged zoologically, so that comparison may be made at once *. 



TAii"R X. — List of Species that occur in the Lower, Middle, and 

 Upper Devonian rocks of North Devon, and in the Carboniferous 

 rocks generally. 



Classes. 



^ 



Plants 



ccelenterata 



Echinodermata 



POLYZOA 



Knorria dichotoma, fioM^^iif 



Adiantites hibernicus, Forbes 



Michelinia antiqua, M' Coy 



Adelocrinus hystrix, Thill 



Cyathocrinus pinnatus ?, Goldf. ... 



variabilis?, Phill. 



Pentremites ovalis 



Ceriopora similis 



gracilis 



Fenestella antiqua ?, Goldf. 



■ plebeia?, ikf^Coy 



prisca ?, Goldf. 



Grlauconome bipinnata, Phill 



Polypora laxa ?, Phill. 



Athyris oblonga, 8ow 



Chonefces sordida, Sow. (C.Hardren- 



sis, Phill.) 



Discina nitida, Phill. 



* Consult Table XI., giving generic and specific values between the Old Eed 

 Sandstone, the British marine and Foreign Devonian beds of Rhenish Prussia, 

 Belgium, and France, and the number of species (fifty-six) common to the 

 Carboniferous. 



