Correspondence — Dr. F. A. Bather — Prof. E. H. L. Schwarz. 479 



I propose, therefore, to publish a double Index to the generic and 

 specific names in the "Synopsis," the names in the first part being 

 arranged alphabetically under the trivial names, while the second part 

 will be an index to generic names, each followed by a list of the 

 species referred to it by Desor. This index will be preceded by 

 a " Note surles dates de publication," drawn up by Mr. Jules Lambert, 

 who has spent many years in ascertaining all the bibliographic details 

 with regard to this work. 



The Index will be printed on paper of the same size as the 

 " Synopsis." 



Should there be as many as eighty subscribers, the price may be as 

 low as five shillings. 



I shall be glad if intending subscribers will communicate with me 

 at the I^atural History Museum, S.W., at an early date, as after 

 publication the price will probably be raised. 



F. A. Bather. 



THE TYGERBERG ANTICLINE. 

 Sir, — I regret to have again to refer to this subject, not that I wish 

 to insist that my explanation of the cause for this fold is the correct 

 one, but that I cannot let a fold described by me as an anticline, and 

 shown to be an anticline even in Dr. C. Sandberg's photograph in the 

 Geological Magazine for July, p. 311, be referred to as a syncline. 

 Dr. Sandberg's photograph is taken on the opposite side of the poort 

 to that from which the photograph in Mr. Rogers' " Geology of Cape 

 Colony " is taken, and the real difference is that the south limb of 

 the anticline is cut away and only appears in the background. In 

 the original communication in the Trans. Geol. Soc. S.A., 1906, 

 vol. ix, Dr. Sandberg records that his study of this fold was pursued 

 during a " stay of a few hours off and on " (p. 82), and geologising in 

 a new and unfamiliar country under such conditions is the only excuse 

 Dr. Sandberg can offer for seeing things upside down. 



Eenest H. L. Schwaez. 

 Albany Museum, 



Box 13, Grahamstown, Cape Colony. 

 August 16, 1908. 



THE TERM 'CREVASSE.' 

 Sir, — In several American books on Physiography the term 

 ' crevasse ' is employed to designate the gap that is occasionally 

 made in natural or artificial levees. Surely such an employment 

 of the term is to be deprecated, seeing that it has for long been used 

 in another connexion. I have also a faint recollection of having seen 

 it used synonymously with the term ' grike.' There are already too 

 many terms in circulation that are used technically in more than one 

 science. In many cases their usage in the several sciences has obtained 

 such general recognition that it is undesirable to suggest any change, 

 but in such a branch of science as river-development this can scarcely 

 yet be argued. In Holland, where incursions of the sea are not 

 infrequent owing to the breaking down of the artificial levees, the 

 term ' eenbroek ' is employed to describe the ' breaking in.' The 



