Yol. XXviii.J PALiEONTOLOGr OP LANCASHIRE COAL MEASURES. 387 



At Trough gate, near Bacup, a band of shale, two feet 

 thick and full of this shell, was cut through in the railway- 

 cutting. The band was hard enough to take a polish, and 

 was locally known as '^ Troughgate Marble.*^ 



Examples are in the Dugdale Collection, M.M., and the 

 museum of the Bacup Natural History Society. 



Naiadites sp. 



Naiadites, the species of which are not mentioned, are 

 stated by Dr. Hind to occur in the Oldham district, 

 immediately over the First Coal above the Millstone Grit, 

 and also high up in the Gannister Series. (Monog. Carbon., 

 &c., p. 161.) 



Above the Upper Mountain Mine at Burrs, half a mile 

 north of Bury. (Hull, Geol. Surv. Mem., Geology of the 

 Country around Bolton-le-Moors, p. 35.) 



S. antiquuSj Hind. 



Roof of Mountain Four Feet, Carre Heys, near Colne. 

 (W 626 and W 627, e coll. Wild, M.M.) 



Lower Coal Measures of Burnley. (L 2081, e coll. Kay- 

 Shuttleworth, M.M.) 



The specimen (W 627) was figured by Mr. Geo. Wild as 



'^Anthracosia, new angular species." Trans. Manch. Geol. 



Soc, Vol. XXI., PI. II., fig. 7. (W 626) is associated with 



ostracods. 



Posidoniella (Posidonomya). 



Posidoniella laevis. 

 This pretty little shell has long been known to Lancashire 

 collectors as Posidonia Gibsoni. It is especially character- 

 istic of the roof shales of the Upper Foot or Bullion Mine 

 and the Mountain Four Feet, where it occurs in great 

 numbers, almost everywhere where these seams are exposed. 

 It also ranges down to the Yoredale shales in the Todmorden 

 Valley, where it was first found. 



