Editofial Contme?tt. 243 
EDITORIAL COMMENT. 
BiBLIOGRAPHIA GeOLOGICA. 
The "Bibliographia Geologica" noted by Mr. J. B. 
Woodvvorth in the Januar}' number of this magazine, which 
M. Mourlon, Director of the Geological Survey of Bel- 
gium, is bringing out with the collaboration of M. G. Sim- 
oens, is of great importance and deserves to occupy the 
first place, and a department all to itself in any future 
edition of the "Catalogue of Geological Bibliographies" 
published under the auspicies of the International Congress 
of Geologists by M. E. de Margerie. 
The extent of this former work is not generally under- 
stood. Briefly the work is divided into two series viz: (A) 
that including the geological papers published anterior to 
Jan. I, 1896; and (B) the works published after that date. 
The first volume of Series A includes 3,000 publications 
found in the library of the Belgium Geological Survey. The 
consecutive volumes of this series will together give a uni- 
versal catalogue of geological literature up to 1896 so far as 
this librar}' can gi\'e it, and when this source has been ex- 
hausted it is the intention of the editors to consult the great 
libraries in foreign countries and then produce a really 
Universal Catalogue for all libraries. 
For the convenience of the subscribers to this colossal 
work the titles will be printed only on one side, so that the 
sheets can be cut and pasted on the catalogue cards of each 
library, the books in its possession being indicated by an 
underscore of these titles. The Dewey decimal system of 
classification has been adopted whereb}' the advantages of 
cross reference are secured at one record of subject, geo- 
graphical relation, and author. 
The prices of the parts alread}' issued are very moder- 
ate. Series A, Vol. I, 378 pp. in 8vo, and Series B, Vol.11, 
372 pp. in 8\'o, cost 8 francs per volume. Series B, Vol. 
I, 215 pp. 8vo, costs 5 francs. A copy of the second edi- 
tion of the "Decimal Classification" of Melvil Dewej- ap- 
plied to geological science &c., costs 2 francs. 
The publications can be had of Hayez, Book publisher 
