640 



PEOCEEDINGS or THE GEOLOGICAL SOCIETY. 



former class 25 are common, and of tlie latter 17 belong to the areas 

 under discussion ; whereas there are only 8 species that pass up to 

 the Carboniferous in any area, viz. 1 Gasteropod (Acroculia vetusta), 

 1 Polyzoon (Fenestella antiqua), 5 Brachiopoda, and 1 Cephalopod 

 {Orthoceras cylindraceum). 



The following Table is compiled to show the occurrence and dis- 

 tribution of all the known species in the Middle Devonian rocks of 

 North Devon and West Somerset in the best-known localities, 

 though many more will yet be added : — 



Table IY. — Distribution of species in the Middle Devonian or 

 Ilfracomhe Group in North Devon and West Somerset. 



Species. 





West Somerset. 





Qantock 

 Hills. 



Croydon 

 Area. 



1 

 1 



1 



1 



So 



1 



4 



I 



o 



a 

 1 



1 

 z 



i 

 1 





i 

 a 



1 



i 



i 



1 



Q 

 1 



1 



1 



5 



Stromatopora concentrica, Goldf. .... 













■Sf 

 ■K- 



■«• 



■«• 



■Sf 

 * 









^<- 



Amplexus tortuosus, Phill. 

















■Sf 











^ 



Acervularia Groldfussii, De Vern 













Cyathophyllum agqiiiseptum, M.-Edw. 







■5f 



... 



'.'.'. 



* 

 ^ 



¥r 



^ 





Damnoniense, Lonsd 























M: 







helianthoides, Goldf. 







^ 



* 



... 



... 









obtortum, M.-Edw 













Cystiphylluni vesiculosum, CroJdf 





^ 



Endophyllum abditum, M.-Edw 















•55- 





Eavosites cervicornis, Blainv 



fibrosa? Goldf. 











... 





■Sf- 







Hallia Pengellii, M.-Edw 













¥: 



Heliophyllum Halli, M. -Edw 





^ 









Heliolites porosa, Goldf. 





■S5- 



45- 





* 

 ^ 



Cyathocrinus macrodactylus, Phill. ... 

 variabilis, Phill. 





•K- 



Hexacrinus, sp 





Tentaculites annulatus, Schloth 





^ 



■ scalaris, Schloth 





Trimerocephalus Isevis, Munst 







Ceriopora similis, -P^f// 





* 

 ■5f 



■5f 

 ■$(■ 



Fenestella anti qua, Goldf. 





artliritica, Phill 





Retepora repisteria, Goldf. 





Athyris concentrica, V. Buch 





Atrypa desquamata, Sow 



reticularis, Linn 













