G64: PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Eed Sandstone, three only being known in the Marine Devonian, 

 viz. Phyllolepis concentricus, Onchus, and Holo^tycJiius (vide Ta- 

 ble II. p. 630-634, for distribution of all the species through the Old 

 Eed series). 



1. Amorphozoa. — Four genera and nine species of this class occur 

 in, and are here noticed as being peculiar to, the Lower and Middle 

 Devonian rocks of Cornwall and South Devon ; one species only, 

 Stromatojpora concentrica, Goldf., is known in North Devon and "West 

 Somerset. They likewise occur in the Ehenish beds of the same 

 age. The singular and typical Spliceros;pongia {Spliceronites) tes- 

 sellata, Phill., is strictly British, and at present is known only in, 

 and confined to, the limestones of the Middle series at Launceston 

 and Woolborough in South Devon. The abundance of Steganodic- 

 tyum in the Lower Devonian slates of Polperro, Eowey and Looe, 

 indeed all along the South Devon and South Cornish coast, from 

 Mudstone bay to Brixham and Powey, as well as on the north coast 

 of Cornwall at Bedruthen, testifies to the widely spread distribu- 

 tion of this hitherto peculiar British species ; and, confined, as it is, 

 to the Lower division of the Devonian slates, careful search will, I 

 believe, reveal one or both of the species in the Lynton area. _ I^o 

 Amorphozoa are known either in the Upper Devonian rocks of any 

 area, or in the Carboniferous group, unless we accept the doubtful 

 genus Tragos, which is peculiar to the Carboniferous Limestone, 

 and which may belong to this class. These nine Lower (and one 

 Middle) Devonian Amorphozoa, amongst other fossils, must there- 

 fore be considered evidence of much value when associated with 

 higher forms which are also strictly Devonian types. 



2. Coelenterata. — The greatest significance must be attached to this 

 class, when treating of the stratigraphical value of the Devonian 

 fossils. They stand alone, and, side by side with certain genera of 

 tUe Brachiopoda, serve especially to distinguish and characterize the 

 Middle Devonian series. No less than 24- genera are known to 

 occur in this Middle division alone, of which the following 15 are 

 confined to it, viz. Acervularia, Arachnophyllum, Battershyia, Cam- 

 popliyllum, Cho7ioj)7iyllum, Emmonsia, Endo])}i.yllum, Hallia, Helio- 

 pliyllum, Metr{oj)hylhim, Fachyj^hyllum, Pleurodictyum, Smithia, 

 SpongiopliyUiim, and Sti^e^Dhodes. These known 24 genera embrace 

 53 species, 52 of which are strictly Devonian, 45 being confined to 

 and characterizing the Middle group alone (see Tables II. and Y.for 

 distribution). Analysis and comparison of the British species with 

 those of the three European areas reveal and give the same results. 



Table YIII. has been constructed to show the remarkable 

 distribution of, and zoological agreement between, the British and 

 Foreign species in space, and their distribution in time also. 



We find that 10 genera and 22 species are identical and common 

 to the four areas, and also to the received stratigraphical groupings 



the World," the substance of six lectures delivered at theEoyal Institution, 1861, 

 Geologist, vol. iv. p. 332, 1861 ; andPengelly "On the Geological and Chrono- 

 logical Distribution of the Devonian Possils of Devon and Cornwall," Geologist, 

 vol. V. p. 10, 1862. 



