430 Correspondence — Mr. A. Smith Woodward. 



declivity " an escarpment," comiDaring it with true escarpments in 

 England and France, and with the cliff-borders of the Nile valley 

 (which are not technically escarpments). He says "all these 

 escarpments have been formed over the surface of emergent lands," 

 that they are absolutely terrestrial, and "that in ascribing a similar 

 origin to those here under consideration we are only drawing a logical 

 deduction from the premises laid down." 



The logic of this does not seem very clear. Can Prof. Hull point 

 to a true escarpment anywhere in Europe which has a length of 

 700 miles and a height above its base of 7,000 to 8,000 feet ? More- 

 over, this so-called escarpment does not stop in the Bay of Biscay ; 

 it is continued round the coasts of Spain, it crosses the mouth of the 

 Mediterranean, and runs down the whole length of Africa. It is 

 part of the elevated shelf on which two continents stand, and Prof. 

 Hull may call it an escarpment if he chooses, but it is not com- 

 parable with ordinary escarpments, and he is not justified in 

 assuming that it has been formed by atmospheric agencies. 



He also tells your readers that " a solid escarpment of this kind 

 indicates a slow continuous elevation after the British platform had 

 been planed down by wave action, and subsequent depression after 

 a lapse of time." Here he assumes that the platform was formed 

 first and the escarpment afterwards. I think most writers have 

 supposed that the great declivity which marks the ancient border 

 of the continent is a much older feature than the platform. 



Finally, we are told that the formation of the platform " may be 

 referred back with confidence to the Mio-Pliocene period, and that 

 of the grand escarpment to the succeeding early Pleistocene or 

 Glacial stage." There are probably others beside myself who would 

 like to have the reasons for this confident assertion. Is there any 

 reason why the formation of the escarpment and the union of Great 

 Britain with Iceland should not have taken place in the Eocene 

 period? That such a union may have been repeated at a later date 

 is quite possible, but I think the history of the features described 

 by Px'of. Hull is much longer and more complicated than he supposes, 

 and I would not like to say that either of them was formed wholly 

 at any one period. 



Prof. Hull may have good reasons for his statements, but he does 

 not give them, and as his conclusions are not the only inferences 

 that may be drawn from the facts, they must be discussed before 

 they can be accepted. A. J. Jukes-Browne. 



VERTEBRATE PALEONTOLOGY. 



SiK, — While thanking you for the gratifying review with which 

 my " Outlines of Vertebrate Palaaontology " are honoured in the 

 August number of the Geological Magazine, I should like to 

 correct two misapprehensions of the reviewer. 



Firstly, it is a mistake to suppose that any "new terms are 

 introduced." All the terms employed are to be found in current 

 literature, and most of them are in nearly universal use. Moreover, 

 on its first mention each term which is not likely to be familiar to the 

 elementary student, is not only printed in italics and briefly defined, 



