80 VAUGHAN : A NOTE ON CAKBONIFEROUS SEQUENCE. 
levels and, in its characters, presents a strong resemblance 
to the form of this species which is abundant, in the uppermost 
beds of the Avonian, in the Gower Peninsula. Corals are rare, 
with the exception of Pseudamplexus nodulosus, ^ species in 
which extreme simplicity of structural plan is combined with 
a knobbed, wrinkled, and twisted outward form — characters 
w^hich indicate extreme decadence. This form is known only 
from (the Cyathaxonia-'Beds), at which level it is of very 
general occurrence. 
Specimens of Posidonomya memhranacea were also collected 
from the shales, and this sheU is recognised by Dr. Wheelton 
Hind as a characteristic Lower Pendleside form. 
It seems, then, that we are justified, at least as a working 
theory, in assigning the Angram Shales to and Lower Pendle- 
side ; but more material and a more careful examination of 
the section, bed by bed, is absolutely necessary before the con- 
clusions liere suggested can be considered to be placed beyond 
dispute. The exliaustive description of the Angram section 
is a duty which Yorkshire geologists would be wrong in shirking, 
and which, I feel sure, will be embraced by them mth avidity 
and carried to a successful issue with characteristic thoroughness. 
It is necessary, at this point, to consider what is known 
concerning the relation of the Pendleside Series to the uppermost 
portion of the Avonian. 
Sections showing a continuous sequence from Avonian 
up into Pendleside are unfortunately extremely rare,* and, 
in the majority of exposures, it is only possible to assert that 
limestones containing a or fauna are succeeded by shales 
containing Posidonomya Becker i. 
*Dr. C. A. Matley has just completed the stratigraphical examination 
of the coast section from Rush to Skerries, in the County of Dubhn. Here, 
there is an unbroken sequence from Cyathaxonia Beds through the Posi- 
donomya Bccheri Beds. He has carefully and exhaustively collected from 
each bed, and has sent the material to me for examination. We may 
consequently hope to finally settle the inter-relation of these two sets of 
beds at no verj^ distant date. 
Dr. Wheelton Hind cites a conformable sequence from Avonian 
into Pendleside at Grange Quarry, near Holloway (Geol. Mag. (1906), 
p. 450), but the beds apparently do not yield a large fauna. 
