VAUGHAN : A NOTE ON CARBONIFEROUS SEQUENCE. 79 
Here the fauna of the shales includes the following 
forms : — 
Spirifer hisulcatics (long- winged form), abundant. 
Productus longispinus (especially the variant, P. 
longispino-concinnus), abundant. 
P. antiquatus. 
P. corrugatus (with Orthotetoid convergence). 
Orthotetes (with strongly-marked periodicity of ribbing). 
Camarophoria sp. 
No corals were found. 
This list affords clear evidence of the sub-zone, but 
does not do more than suggest a particular level wdthin that 
sub-zone. 
The occurrence of P. longispino-concinnus, of a variant of 
Spirifer hisulcatus with extremely elongated wings, and of a 
variant of P. corrugatus wdth a very specialised type of ribbing, 
suggests a time posterior to that at which the normal forms of 
these species flourished, and therefore a high level in D^. The 
evidence is, however, inconclusive, in that deviation from the 
normal may be a consequence of variation in conditions, rather 
than of evolution in time. 
In the South- Western Province, similar forms occur at 
the very top of in a similar Uthological environment, but, 
since we have no knowledge of the fauna which accompanies 
the same conditions during the main period, we are unable 
as yet to make a more definite assertion as to horizon. 
(2) At the Angram Water Works Section, the black shales 
pass upward without apparent break into the ' Millstone 
Grit,' and the fact that the complete estabHshment of ' Grit ' 
conditions is preceded by siHceous bands in the upper portion 
of the shales strengthens the evidence for continuity of sequence. 
In so far as I was able to judge from an extremely incomplete 
examination of the section, the fauna of the shales at Angram 
differs from that of the shales at Lolley Scar Qaai^ry in several 
important respects. 
Brachiopods are not in great abundance ; Spirifer hisulcatus 
is apparently uncommon, and Productus longispinus was not 
recorded. Martinia glabra is, however, common at certain 
