Professor E. J. Garwood— Horizon of Archeosigillaria. 117 
VIJ.—On tur Horizon or tHE Lower CarsonirErous BrEps con- 
TAINING A RCW.EOSIGILLARIA VANUXEMI (GOppERT) Av Mearnop FELL. 
By Professor E. J. Garwoov, M.A., Sec. Geol. Soc. 
Fr a note on Archeosigillaria Vanuxemi and Bothrodendron sp., 
published in the Gxonoeican Magazine for February last, 
Mr. J. W. Jackson speculated on the age of the beds at Meathop, 
in which these plant remains occur, and refers to the general 
classification of the Lower Carboniferous rocks of the Westmorland 
district, which I gave in this magazine in 1907.' He remarks: ‘‘ It 
is perhaps premature to attempt to fix definitely the exact horizon of 
these beds, as they appear to have been as yet but superficially 
studied.” * Since the classification above referred to was published, 
I have devoted such time as could be spared from professional duties 
to an exhaustive examination of the whole northern area, the result 
of which has been to confirm the general conclusions already given in 
this magazine. In my forthcoming account of the district, I have 
given a detailed description of the. Meathop section. ‘The delay in 
publishing a full account of the northern area has been necessitated 
by the general structure of the district, which required a careful 
study of isolated outcrops, extending over a very large area, before an 
accurate co-ordination of the separate exposures could be established. 
If any justification for this delay were needed, it is supplied by 
Mr. Jackson’s note, in which he confesses his inability to decide upon 
the age of the beds displayed in the isolated exposure at Meathop on 
the evidence afforded by the collections obtained during his visits to 
that locality. 
On my iirst visit to this section some years ago I obtained only 
a scanty fauna, giving inconclusive evidence of the horizon, and it has 
required very careful and close collecting during repeated visits 
before the beds could be definitely correlated with those occurring in 
other portions of the district where the horizons could be accurately 
determined. Pending the publication of my detailed description it 
may therefore be of interest to give here the conclusions arrived at 
regarding the age of the Meathop beds and the evidence upon which 
it is based. 
My further work in the district since the provisional classification 
was published proved conclusively that the Meathop beds were 
correctly correlated with the lower dolomites of Shap and Brigsteer, 
and represent the lower portion of Dr. Vaughan’s C horizon in the 
Bristol area. ‘This is clearly shown by a comparison of the Meathop 
fauna with that of the beds in the Shap exposures. In my previous 
notes I laid emphasis on the importance of the Arnside Michelinia 
bed as furnishing a definite horizon in the northern sequence, and 
regretted the absence of beds containing this characteristic fauna from 
the Shap district. At the same time I gave evidence in support of 
the contention that the IWichelinia megastoma bed must be represented 
in that district by the base of the Ashfell Sandstone, or by the top of 
the Shap dolomite. This contention has now been fully corroborated 
by the finding of Mchelinia itself in the Camarophoria isorhyncha 
1 Gror. Mac., 1907, Dec. V, Vol. IV, pp. 70-4. 2 See table, op. cit., p. 73. 
