R. Bullen Newton — Nummulitic Rock, 8.E. Africa. 487 



rocks are generally, except at Nuneaton, affected by forces which 

 acted at right angles to this. 



Professor Lapworth, when with me in Charnwood, succeeded 

 in finding a worn burrow in the slates low down in the Brand 

 Series, and Mr. Ebodes has since obtained one or two additional 

 examples ; these are the first undoubted fossils found in the Forest. 



IV. — Note on the occurrence of Nummulitic Limestone in 

 South-Eastern Africa. 



By E. Bullen Newton, F.G.S. 



(PLATE XV.) 



THE object of this communication is to place upon record the 

 existence of Nummulitic rocks in South-Eastern Africa ; 

 the result of an examination of specimens brought me by their 

 discoverer, Mr. David Draper, F.G.S. , of Johannesburg, the 

 enterprising Secretary of the Geological Society of South Africa. 



The specimens, comprising two pieces of limestone, were 

 obtained in situ from a spot about 100 miles westward of the 

 mouth of the Busi River in Gaza-land. One is of a light-greyish 

 colour, the other pink or flesh-tinted, and both are crowded with 

 foraniini feral tests in a good state of preservation. Some of the 

 organisms are exhibited in relief on the weathered surfaces, either 

 as sections or exteriors, though for structural details it was necessary 

 to prepare microscopical slides. When these were completed I was 

 able to determine the presence of two rather important species, 

 viz. Nummulites perforata and Nummulites Biaritzensis, both of 

 which occur in abundance in Madagascar, India, and other 

 localities. 



Professor Rupert Jones, F.R.S., who most kindly undertook to 

 examine the sections, not only confirmed my identifications, but 

 was likewise able to point out some other forms, such as Nummulites 

 Guettardi, N. planulata, and varieties of Orbitoides papyraceus. 

 Professor Jones was inclined to regard the N. perforata as more 

 closely allied to N. Ghizensis of the Pyramids, but as Orbitoides 

 is absent in the Egyptian limestone he felt satisfied as to the 

 correctness of the former name. Most of the species referred to 

 are found in the ligbt-coloured rock, the pink material yielding 

 the forms of N. Biaritzensis and Orbitoides. Both large and small 

 examples of N. perforata are present, the former measuring in their 

 longest diameter 15 millimetres, and having an extremely small 

 nucleus ; the latter being only three or four millimetres across and 

 possessing very large initial chambers. This difference in the same 

 species forms a good illustration of the phenomenon usually alluded 

 to as dimorphism. 



Mr. Draper informs me that there is a large development of this 

 limestone, and although at present without any accurate details of 

 the beds, he hopes soon to return to this part of Africa, when he 



