ANNIVERSARY ADDRESS OF THE PRESIDENT. 



181 



52 species, no single form passes to the Carboniferous, and none are 

 common to the Silurian rocks in any area ; they stand alone, and 

 are sufficient in themselves to maintain the integrity of the Devonian 

 system. This is equally definite and distinct throughout the Euro- 

 pean or American areas, or wherever the -Devonian rocks are deve- 

 loped. 15 genera illustrate the Zoantharia rugosa and 8 the Z. tabu- 

 late. The genus Acervularia numbers 7 species, Alveolites 4, Gya- 

 thojphyllum 12, Favosites 5, Smithia 3, Endojohyllum 2, and Petraia 2. 

 The remaining 18 genera are only represented by 1 species each ; 20 

 species are common to the rocks of North and South Devon, and 25 

 occur on the continent (Rhenish Prussia, Belgium, and Prance) ; 

 none pass to the Carboniferous rocks in any region. The Lamelli- 

 branchiata, Gasteropoda, and Cephalopoda are all of equal strati- 

 graphical value. The Middle Devonian group contains all the 24 

 genera and 48 of the 52 species. The Lower Devonian has hitherto 

 only yielded 4 genera and 7 species ; the latter are Alveolites sub- 

 orbicidaris, Oyaihophyllum helianthoides, Petraia celtica, P. gigcts, P. 

 pleuriradialis, P. bina'l, and Pleurodictyum problematicum ; and the 

 Upper Devonian also 4 genera and 7 species, viz. Ampleceus tortuosus, 

 Cyathophyllum ccespitosum, C. ceratites, Fistulipora cribrosa, Michelinia 

 antiqua, Petraia celtica, and P. pleuriradialis. The researches of Dr. 

 Nicholson upon the Devonian Corals of North America have thrown 

 much light upon their history, habits, and mineralization ; and it is 

 to be hoped that his labours will be embodied in a volume upon the 

 Rugose Corals, equal in interest and value to his late contribution on 

 the Tabulata. Doubtless the Paheozoic Actinozoa of the British 

 rocks now require critical revision, especially the Silurian and Car- 

 boniferous groups. 



The Upper and Lower Devonian rocks are chiefly composed of 

 slates, with here and there impure limestones. They therefore 

 possess no coral fauna : whereas the highly developed masses of 

 limestone around Torquay and Newton Abbot are simply Devonian 

 coral reefs of great magnitude. In North Devon, between Ilfra- 

 combe and Linton, the limestones are lenticular, thin, and im- 

 pure ; yet more than one half of the entire known Devonian Acti- 

 nozoa have occurred in them, and we have evidence of beds below 

 at low-water level near Ilfracombe yielding even finer specimens 

 than at Torquay. They have to be searched for in North Devon 

 and West Somerset ; patient working over that extensive area be- 

 tween Barnstaple and the Poreland with unbiassed views and a 

 knowledge of the fauna which exists altogether independent 

 either of the Silurian or Carboniferous, would readily convince 

 those who have never examined the county that the rocks of North 

 Devon between Baggy and the Poreland have nothing whatever to do 

 with the Carboniferous system. The fossils alone, setting aside strati- 

 graphical evidence and succession, determine the relation of this 

 area to Belgium, the Rhine, and Prance ; and their continuity under 

 Somersetshire, Wiltshire, Berkshire, and Middlesex on to the continent 

 is no longer matter of doubt or speculation, for the philosophical 

 and far-seeing views and hypotheses of Mr. Godwin-Austen and Prof. 



VOL. XXXVII. o 



