390 Proceedings of the Royal Irish Academy. 



Madras implements, leaving it to those who may desire to go deeper 

 into the question to refer directly to Mr. Foote's memoir.* 



Together with Mr. King, Mr. Foote has, in the districts of Madras 

 Proper and North Arcot collected many hundreds of chipped quartzite 

 implements where they were found, either washed or eroded out on 

 the surface of laterite gravels and conglomerates, or embedded in 

 situ at depths of from three to eight, or even ten feet beneath the 

 same. 



Mr. Foote's reasons for concluding that the Madras implements are 

 of the same age as the laterite are three-fold. Firstly, when occur- 

 ring on the surface they are invariably associated with the detritus 

 from laterite beds, and they do not occur in the younger alluvial for- 

 mations which separate areas of laterite. Secondly — the implements 

 all bear a colour and stain of the matrix of laterite in which they 

 were embedded, precisely similar to that found on the miscellaneous 

 quartzite shingle also occurring in and on the laterite, and which,, 

 from its abundance, cannot have been transported in comparatively 

 recent times to its present position by human agency, as has been sug- 

 gested for the implements. Thirdly — there is the already mentioned 

 fact that the implements are sometimes found firmly embedded in the 

 laterite, though this fact is not quite so conclusive as might be at 

 first supposed, since it is just possible that the particular bed includ- 

 ing the implements might consist of re-assorted detrital laterite, and 

 not of the original formation. That the bed does belong to the origi- 

 nal formation is, however, in Mr. Foote's opinion, most probable. 



The term laterite, which I have used above, may possibly convey no 

 very distinct meaning to the English reader; it is one applied to a form 

 of rock which is only doubtfully represented in any country other than 

 India. Be this as it may, the name is at present used exclusively in 

 reference to an Indian post-tertiary formation, which, though vary- 

 ing in composition and structural characters, is constant in this one 

 respect — that it is an indurated clay containing a greater or less per- 

 centage of ferruginous constituents with occasional nests of lithomarge. 

 It is either cellular, pisolitic, or conglomeritic in structure, and is pos- 

 sibly separable into several groups of different ages. 



There are good reasons for believing that it at one time covered 

 over nearly the whole of India as with a film, several hundred feet 

 thick, which accommodated itself to the previously existing inequali- 

 ties of the surface. It is now found in isolated caps on the tops of 

 some of the loftiest plateaus of the central parts of India, and forms a 

 marginal zone along both the eastern and western coasts. That it is a 

 subaqueous deposit seems necessary from its characters ; but whether 

 formed under fresh water or the sea it is impossible to say, since it has 

 not yielded any fossil fauna or flora. The marginal zone, which con- 



* For references to Mr. Foote's Papers see the Table accompanying this Paper, 

 p. 403. 



