﻿206 DE. A. VATJGHAN ON THE PALiEONTOLOGICAL [May I905, 



Zap hrentis -Zone (Z). 



Lithological character. — Massive limestones, usually very 

 encrinital. 



Exposure. — Massive limestones crowded with brachiopods, ex- 

 tending some 450 feet westward from Kingrove-Farm Bridge. 



Fauna :— 

 Corals : 

 Zaphrentis aff. Phittipsi. \ Syringop>ora sp. 



Brachiopods : 



Cliothyris Eoyssii (rnut.). 

 Cliothyris glabristria. 

 Spirifer aff. clathratus and variety. 

 Eeticularia aff. lineata. 

 Syringothyris aff. cuspidata. 

 Leptena analoga. 



Orthotetes crenistria (mut. Z). 

 Schizophoria resupinata. 

 Productus cf. Martini. 

 Chonetes cf. hardrensis. 

 Chonetes pa/pilionacea. 



Subdivisions : — 



(1) Horizon /3. 



Since Zaphrentis has not been found below the resupinata- 

 subzone, and no specimen of Spiriferina octoplicata has been 

 met with in - the section, this horizon at Sodbury has no 

 characters other than those common to the whole clathratus- 

 subzone, of which it forms the base. 



(2) clathratus- sub zone (Z x ). 



This subzone is well characterized by the extreme abund- 

 ance of Spirifer afT. clathratus and its variety. 



Orthotetes crenistria, in the mutation characteristic of the 

 Zaphrentis-Zcme, is abundant. 



Leptena analoga and Chonetes cf. hardrensis are common. 



Cliothyris glabristria, Reticularia aff. lineata, Cliothyris 

 Eoyssii (mut.), and a Syringopora are not infrequent. 



Productus cf. Martini is only recorded doubtfully. 



(3) besupjnata- sub zone (Z ). 



This subzone is well defined by the abundance of Clio- 

 thyris glabristria and Schizophoria resupinata, as well as by 

 the fact that in it Zaphrentis attains its maximum. 



Chonetes cf. hardrensis crowds the beds at the bottom of the 

 subzone, while, at the top, Chonetes papilionacea is the 

 predominant form and is equally prolific. 



Syringothyris aff. cuspidata occurs abundantly in the lower 

 half of the subzone, and that mutation of Orthotetes which is 

 characteristic of the Zaphrentis-Zone is common throughout. 



Leptena and Productus cf. Martini (large form aff. Pr. semi- 

 reticulatus) are met with not infrequently. 



Syringopora 6 has been noted at two levels. 



(4) Horizon y. 



This horizon is not defined with precision, since no specimen 

 of Caninia has been found in association with Zaphrentis ; 



