332 ME. T. F. S1BLT ON THE CARBONIFEROUS [May 1906, 



Special faunal characters: — 



Corals : 



The zone is specially characterized by : — 



(1) The common occurrence, at recurring levels, of Caninia cylindrica, 



muts. (especially mut. S ls in the uppermost part), Caninoid Cyatho- 

 phylla, and Caninoid Campophylla ; and of Cyathophyllum <p, which 

 ranges throughout the upper and main part, and attains its maximum 

 in the uppermost beds. 



(2) Michelinia megastoma, which is abundant in the lower part, and has not 



been recorded outside this zone. 



(3) Syringopora cf. reticulata, which, as an abundant form, is highly 



characteristic of the lower part of the zone, although it ranges through- 

 out and persists into the succeeding subzone. 



Zaphrentis aff. cornucopia?, mut. C, is characteristic, and has been 

 recorded throughout the greater part of the zone. Z. aff. Phillipsi 

 occurs only in the lowest part of the zone. 



Amplexus sp. occurs somewhat rarely. 



Early Clisiophyllids occur very rarely. 



Lithostrotion cf. irregulare, which is the first representative of the 

 genus, occurs in the topmost beds. 



Brachiopods: 



The zone is specially characterized by : — 



(1) The maximum of Syringothyris aff. cuspidata, mut. C. This mutation 



ranges throughout, but it is very scarce in the uppermost beds, 



(2) The great abundance of Ortkothetes aff. crenistria, mut. C, at recurring 



levels throughout. 



(3) Froductus concinno- Martini, which is common throughout the main 



part. 



(4) The abundance of Chonetes cf. comoides at certain levels, especially in the 



lower part. 



Spirifer aff. claihratus persists throughout the main part of the 

 zone, and is not uncommon in the lower part. Sp. cf. bisulcatus 

 is not uncommon in the upper and main portions. 



Syringothyris aff. laminosa occurs very sparingly throughout. 



Athyris cf. eapansa is common throughout the upper and main 

 portion of the zone. Beticularia cf. reticulata ranges throughout, 

 and is common at certain levels. 



Seminula ambigua is characteristic of the upper part of the zone. 

 S. aff. fieoides enters sparingly in the uppermost beds. 



Schizophoria aff. resupinata attains its maximum immediately 

 above Horizon y, and is there very prolific, but it does not persist 

 far into the zone. Rliipidomella aff. Michelini, although greatly 

 diminished in numbers, persists commonly throughout. 



Productus aff. Cora, mut. C, which is characteristic of tbis zone 

 and the succeeding subzone, attains its maximum. Pr. 6 enters, 

 and can be found occasionally throughout the upper and main part; 

 it is locally abundant at certain levels. 



