366 PROF. S. H. REYNOLDS AND DE. A. VATJGHAN ON [Aug. I9I I, 



Canikia Zone (C). — The Mid-Avonian. 



Horizon y (base of C ). 



The one important change from the Z fauna is the introduction 

 of the large vesicular Caninids. Speaking in terms of zonal time, 

 we may say that these large Caninids suddenly and simultaneously 

 attained dominance from the East of Belgium, across England and 

 Wales, to the West of Ireland. In Belgium their history can be 

 traced back with certainty to late Devonian time, but, even in this, 

 the country of their birth, it was not until the beginning of C time 

 that they became the most important factor of the coral fauna. 



In y at Burrington the large Caninids are associated in the 

 main with Z 2 forms ; but combined with these are a few rare, though 

 highly interesting, ancestors of the incoming Visean fauna. 



Corals : — 



Amplexus coralloides Sow., including a very large form. 



Zaphrentis densa Carruthers. 



Zaphrentis konincki E. & H., Carruthers. 



Menophyllum temci marginatum E. & H., de ICon. ; determined by 

 Mr. Carruthers. Kare. 



Caninia cornncopice Mich., Carruthers: the cornu-bovis stage is fre- 

 quently well marked. Very common. 



Endophyllum burringtonense, sp. nov. : larger forms than in Z . 



Caninia patula Mich., Salee: a cyathophylloid Caninid. Abundant. 



Caninia densa Salee. 



Cyatho2ohylhim (?) 9 Vaughan ; strong Caninoid affinities. Common 

 and diagnostic of this horizon. 



Cyathaxonia cornu Mich. Not common. 



Ciisiophyllid, an early representative of a C-S gronp. 



Brachiopods: — 



Productus aff. punctatus (Martin) : early mutation, convergent early 



Pr. scabriculus. 

 Spirifer aff. striatus (Martin) : early mutation, convergent Sp><clathratus. 

 Spirifer pinguis Sow. Rare. 

 Spirifer konincki Dewalque ( — Spirifer ductus de Kon. and auctt., 



non A. de Keyserling). Abundant in one band. 

 Athyris aff. glabristria (Phill.), and a variant of Seminuloid form. 

 Athyris aff. lamellosa (L'Eveille). Not common ; the dominant Athyrid 



in Belgium. 



Cyathaxonia cornu and Athyris lamellosa are both greatly more 

 abundant at y in Belgium than in the South- Western Province ; and 

 the same remark is true of Spirifer konincki, which is the zonal 

 index of these beds in Belgium, and there, as in parts of the South- 

 western Province, occurs also in Z 2 . Spirifer pinguis is extremely 

 common in. the Waulsortian phase of this level and C v both in 

 Belgium and in Ireland (County Dublin and County Clare). 



Cj : including a lower series of y type and an upper, dolomitic 

 series. 



Corals : — 



Amplexus coralloides Sow. 



Zaphrentis densa Carruthers. 



Caninia cylindrica (Scouler) Salee. Abundant. 



