Reports & Proceedings — Geological Society of London. 331 



The district of May Hill comprises a small area of ashy grits, 

 which Dr. Callaway in 1900 considered to be of Pre-Cambrian age. 

 The evidence now available does not seem to warrant any definite 

 opinion as regards the age of these beds. Llandovery sandstones 

 are extensively developed, and are of Upper Llandovery age. They 

 consist of a lower division of coarse sandstones and conglomerates, 

 and an upper one of fine sandstones. No beds of Tarannon age 

 occur. 



The "Woolhope Limestone is never thick, and fossils in it are 

 verv few. The Wenlock Shales and Limestone show a normal 

 development. The latter is very fossiliferous, and shows coral- 

 masses in the position of growth. 



The Ludlow Beds are, in the main, of a brown sandy nature. 

 No Aymestry Limestone is present, and the Ludlow Beds cannot 

 be separated into an upper and a lower division. A bone-bed is 

 seen at the top of the Ludlow Beds by the side of the road near 

 Blaisdon. This was described by H. E. Strickland in 1863, who 

 saw it in the railway-cutting close by. 



Downton Sandstone occurs in the north of the district, where it 

 is about 300 feet thick; but it is only some 11 feet thick near 

 Blaisdon on the south. It is conformably overlain by Old lied 

 Sandstone. 



The Silurian rocks are arranged in an anticline in the part of 

 the district where May Hill is, but elsewhere show no such 

 arrangement. On the north they are much broken by faults. 

 Near Flaxley, in the extreme south, rocks from the Wenlock Shale 

 to the Old Ked Sandstone inclusive are overfolded. 



Dr. F. R. C. Reed describes a new species of Lichas from the 

 Wenlock Limestone and a new variety of Calymene papillata. 



2. " The Petrographv of the Millstone Grit Series of Yorkshire." 

 By Albert Gilligan, D.Sc, B.Sc, F.G.S. 



Since the pioneer work of Sorby on this subject, published in 

 1859, the clastic deposits of the Carboniferous System have been 

 unaccountably neglected by petrologists. The author has followed 

 the usual methods of investigation, and has collected a large 

 number of pebbles and specimens from widely separated areas 

 which have been examined microscopically. Numerous separations 

 of the heavy minerals have also been made from all types of rock, 

 varying from coarse conglomerates to shales, which occur in the 

 series. 



Quartz-pebbles are dominant, and vary much, both in size and 

 in colour. The largest are found in the coarse-grained beds at the 

 bottom and top of the series. They often show double-sphenoid 

 forms suggestive of derivation from mechanically deformed rocks, 

 which inference is shown to be correct by the undulose extinction, 

 the crenulate and mylonized structure seen when sections of them 

 are examined in polarized light. 



Blue and opalescent quartz is very common, containing inclusions 

 often of indeterminable character arranged in streams or rows ; 

 others contain liquid with movable bubbles, while needles and 

 hair-like inclusions are also usually present. The quartz of the 



