﻿234 DR. A. VAUGHAN ON THE PALJEONTOLOGICAL [May I905, 



(c) Along the edge of the Downs, between the top of Pembroke 

 Road and the Fountain, higher beds come in very gradually, 

 as the southern edge of the Downs nearly coincides with 

 a line of strike. Between College Road and the Fountain, 

 the lowest part of the IHbunophyllum -Zone is shown, as 

 evidenced by : — 



Lithosirotion Martini. 

 Syringopora cf. clistans 

 Cyathophyttum Murchisoni. 



Dibunophyllum spp. 

 Product us ' gigant&us. 



These exposures merely confirm the sequence in the Avon 

 section, and could have been foretold by continuing the lines of 

 strike across the map. 



(2) In Westbury Park, near Cold-Harbour Farm, 



The Carboniferous Limestone is here exposed, dipping at a high 

 angle, and the Rhsetic rests unconformably upon it. 



The Seminiila -Zone (probably the lower part) is shown by — 

 Seminula sp. and Productus 6 (?). 



(Fossils are scarce and poor, and the exposure is very small.) 



(3) NearSouthmead (three quarters of a mile east of Westbury- 



on-Trym). 



The laminosa-subzone is excellently shown in the large quarries 

 near Southmead. The following divisions are exhibited (in ascending 

 order) : — 



The ' iaminosa-dolomite' (here only slightly dolomitic, but conspicuously 

 encrinital). 



The ' Caninia-Oolite,' resting upon an extremely-fossiliferous band (as is 

 usual throughout the Bristol area). 



The lowest becls of the ' Caninia-D olomites ' (thinly-bedded compact lime- 

 stones). 



The following fossils have been collected, from the top of the 

 Iaminosa-dolomite and from the base of the oolite : — 



Syringothyris aff. laminosa (common). 



? Seminula sp. (rare). 



Orthotetes crenistria, muts. Z & C (very 



abundant). 

 ? Rhipidometta aff. Michelini (rare). 



Chonetes cf. hardrensis (not common). 



Ckonetes aff. papilionacea and Ch. cf. 

 comoides (extremely abundant). 



A Zaphrentid (cf. Caninia) is occa- 

 sionally seen, sectioned in situ. 



This horizon is of considerable interest, since it shows the first 

 appearance of a Yisean fauna at the top of the Toumaisian. 



The cornute Zaphrentid, Chonetes cf. hardrensis, ffldpidomella 

 aff. Michelini, and the convex, grooved Orthotetes (cf. var. Kellii), 

 are characteristic survivors from the Zaphrentis-Zone. 



Seminula sp., Chonetes jpapilionacea in its convex, thick-shelled 

 mutation {Ch. cf. comoides), and the mutation of Orthotetes crenistria 

 which exhibits strong periodicity of ribbing, combined with con- 

 spicuous reticulation, are characteristic of the Visean stage. 



