R. F. Tomes — Liassic Madreporaria. 107 



the origin of the rock. But while I cannot positively assert that 

 some of the rocks included in series A (Older Gneissic Group) may 

 not be rocks of igneous origin, to which a schistose structure has 

 been imparted by subsequent pressure, I think it highly probable 

 that they assumed their present character at a very remote period in 

 the world's history, and may remark that this difficulty is one which 

 frequently confronts us in examining the older Archaean series. But, 

 while admitting this uncertainty, I observe in some of the specimens 

 the structures which I have been accustomed to note as characteristic 

 of the older gneisses, and was independently struck with the resem- 

 blance which some of them presented to specimens collected by 

 myself in Canada and in N.W. Scotland, especially in the case of 

 (13), which is very like to a " quartzose gneiss," high in the Grenville 

 series, shown to me by Sir W. Dawson in 1884, near Papineauville 

 Station on the Ottawa river. Thus the series as a whole may safely 

 be regarded as petrologically " homotaxial " with the middle part of 

 the Canadian Laurentians. 



IV. — On the Occurrence of Two Species of Madreporaria in 



the Upper Lias of Gloucestershire. 



By Robert F. Tomes, F.G.S. 



THE few recorded Madreporaria of the Upper Lias possess con- 

 siderable interest on account of the great generic as well as 

 specific differences which exist between them and those from the 

 Middle and Lower Lias, though it might seem probable that the dis- 

 covery of a greater number of species would diminish that dis- 

 crepancy. Such a conclusion has not, however, by any means been 

 substantiated by further acquaintance with those from the Upper 

 Lias of the district of which I am about to speak. 



The late Mr. Charles Moore in his exhaustive paper, " On the 

 Middle and Upper Lias of the South-West of England," l gives 

 sections of the Upper Lias exposed in quarries on the hills at Stanley 

 and Dumbleton. Both these places are in the eastern part of 

 Gloucestershire, and a reference to the paper above quoted will show 

 that the sections there very closely resemble each other. The quarry 

 on Stanley hill is now closed, but a waste heap yet remains, on the 

 upper surface of which are numerous little hillocks of weathered 

 clay and shale. They represent the barrow loads of clay from near 

 the bottom of the quarry, which have been wheeled out by quarry- 

 men preparatory to lifting the Middle Lias Marlstone below. The 

 influence of weather having first reduced these hillocks to a light 

 blue or grey mud, and afterwards dried them into the consistency of 

 ashes, a considerable number of small lenticular corals were found 

 on their surface, and many were collected during the summer of 1885 

 by my friend Mr. T. J. Slatter, and myself. Belemnites occurred in 

 great abundance, as well as small Ammonites (probably Ammonites 

 Hollandrei) , but although in near association with the corals, they 

 were not found mixed together. In much nearer approximation were 

 1 Proceed. Somerset Arch, and Nat. Hist. Soc. vol. xiii. 



