Vol. 67.] FROM THE SOUTH WALES COALFIELD. 151 



Fouquea cambkensis Allen, 1901. 



Two previous occurrences of insect- wings are recorded from the 

 South Wales Coalfield. Mr. H. A. Allen l described and figured a 

 wing found in shale overlying the 4-foot seam in the Lower Coal 

 Measures of Llanbradach Colliery (Cardiff), to which he gave the 

 name of Fouquea cambrensis. The genus Fouquea, to which Mr. 

 Allen referred his specimen, was created by Charles Brongniart, 2 

 who pointed out its close agreement with Lithomantis in the 

 neuration, while it greatly differs in its reticulation, the nervules 

 being so numerous as to anastomose and form a complex network. 



Archimylacris (Etoblattina.) woodwardi Bolton (1910). 



In the early part of 1910 I described 3 a new species of cockroach, 

 Archimylacris (Etoblattina) ivoodwardi, from a tegmen found by 

 Mr. David Davies, F.G.S., in dark blue shale overlying the JSTo. 2 

 Khondda coal-seam at Clydach Vale. Both these horizons are 

 represented in the collection obtained by the Geological Survey. 



II. Geological Horizons. 



The specimens now to be described are nine in number, and have 

 been obtained from the Mynyddislwyn Vein, the Swansea 4-foot 

 seam, the Graigola Seam, and the well-known Khondda No. 2 Seam. 

 The Mynyddislwyn Vein is a noted house-coal, and is taken by the 

 Geological Survey as the base of the Tipper Series of Coal Measures. 4 

 It is generally correlated with the Llantwit No. 3, the 4-foot or 

 Maesmawr Seam, and the Bedwas Vein. 



The officers of the Geological Survey regard the Wernffraith or 

 4-foot Seam of Swansea as the equivalent of the Mynyddislwyn Vein 

 of Monmouthshire ; but by some authorities the Graigola seam is 

 believed to correspond to that vein. 5 In accordance with the 

 former view, the Swansea 4-foot Seam (under a variety of names, 

 such as Llanelly 6-foot, Box Big Vein, Primrose Seam, and Broad 

 Oak Vein) forms the base of the Upper Series in the Swansea 

 district, just as the Mynyddislwyn Vein does in the Monmouth 

 area. 6 



The Graigola or 6-foot Vein lies 250 yards below the Swansea 

 4-foot Seam, aud is therefore, according to the Survey classification, 

 in the Pennant Series. The Rhondda No. 2 Seam occurs at the 

 base of the Pennant Series. 



If we take the Geological Surveyors' view of the correlation 



1 Geol. Mag dec. iv, vol. viii (1901) pp. 65-68. 



2 ' Kecberches pour servir a l'Histoire des Insectes fossiles des Temps 

 primaires ' St. Etienne, 1893, p. 372. 



3 Geol. Mag. dec. v, vol. vii, pp 147-51 & pi. xv. 



4 ' Geology of the Country around Newport ' Mem. Geol. Surv. 1909, p. 76. 



5 ' Geology of the Country around Swansea ' Mem. Geol. Surv. 1907, 

 pp. 34, 35. 



6 Ibid. pp. 33, 35, 104. 



