76 VAUGHAN : A NOTE ON CARBONIFEROUS SEQUENCE. 
identical with that of the Rownham Hill Quarry, in the typical 
sequence of the Avon Gorge (Bristol). 
Corals. — Clisiophyllids : 
Lonsdaleia, Dibunoyhyllum (of advanced struc- 
tural type, cf. Dib. xj/), Acrophyllum, 
Cyclophyllum. 
Lithostrotions : 
Siphonodendron irregulare and S. junceum. 
N ematophyllum Portlocki and N. M'Coyanum. 
Brachiopods : — 
Spirifer planicosta and S. hisulcatus. 
Producius ' giganteus' P. antiquatus, and P. longispinus. 
Reticularia imbricata and ' i?.' lineata. 
Digression. 
For the benefit of those who are unacquainted with the 
results of recent work upon the Carboniferous Sequence, the 
following broad outline is inserted. 
The Avonian of the South Western Province is divided into 
two great divisions. 
With the lower of these two divisions we are entirely 
unconcerned ; it is certainly unexposed in the Pateley Bridge 
area and, if a boring were made (say at Greenhow Hill) through 
the underlying Carboniferous Rocks, this division would most 
probably be found to be entirely absent (v.i.). 
Tlie Upper Division (or Kidwellian) may be very approxi- 
mately defined as the range of Lithostrotion. It is sub-divided 
into two zones, namely, the Seminula -Zone below, and the 
Dibunophyllum-Zone above. 
If such a boring as has been conceived above were carried 
out, it would most probably pass through part at least of the 
Seminula-Zone, before striking rocks of much greater antiquity. 
Be this as it may, the Umestones which are actually exposed at 
the surface, in the immediate neighbourhood of Pateley Bridge, 
belong to the Dibunophyllum-Zone and, in so far only as the 
exposures which I visited are concerned, to the upper part 
of that zone (D^ or the sub-zone of Lonsdaleia). 
