Reviews — Foraminifera of Belgium. 
327 
The synonymy of the sub-divisions is as follows : 
Panopcea Menardi Sands : (Black) Edeghem Sands. 
Pectunculus pilosus Sands : Shelly glauconitic Sands, Dumont and 
Dewael ; Black Sands of Fort Herentbals, Nyst, 1813 ; Blaclc or 
Lower Antwerp Crag, Lyell and Dewael : Black Antwerp 
Sands, Omalius d’Halloy, Dujardin, and Mourlon. 
Gkayellt Sands of Antwerp and Diest. 
Green Sand, Dujardin, Mourlon, and Cogels ; Diestian System, 
Glauconitic Diestian Sand. Ferruginous Sand and Grit, Dumont; 
Diest Sands, Omalius d’Halloy, d’Archiac, Lyell, Dewalque, 
and Mourlon. 
Throughout the forination of this series subsidence was going on 
to the N.W. and emergence to the S.E., so that each zone overlaps 
the N.W. edge of its predecessor, but does not reach its S.E. border. 
The Middle and Upper Antwerp Sands (corresponding to the 
English Coralline and Red Crags respectively) follow, and will be 
described in a future memoir. 
As against the placing of the Lower Sands in the Miocene or 
terming them Diestian, it is urged that the break between the 
Oligocene or L. Miocene and the Lower SaDds is greater than any 
break in the whole Antwerp Series, and the principal break in 
the latter is between the Middle and Upper divisions, both ad- 
mittedly Pliocene (Scaldisian). 1 
Lists of fossils of the Lower Sands are given, relative abundance, 
ränge, etc., being shown. With a caution as to the effect of bathymetric 
differences and the incompleteness of our knowledge of the existing 
fauna, the relative numbers of extinct and recent species are stated 
to be as follows : Panopcea Menardi zone 44 per cent. recent ; 
Pectunculus pilosus zone 51 per cent. recent, or on the average 47 
per cent. for the whole. 47 per cent. occur in the English Coralline 
Crag, and 51 per cent. in the English Crags generally. 
The Lower Sands ränge from N. France into Holland and N.W. 
Germany, but there is no evidence that they ever extended into 
England, as the pebbles of rock of that age in the Basement Beds 
of the Coralline and Red Crags may have been derived from the 
Belgian area. Traces of the Gravelly Sands occur on the Kentish 
Downs (these are regarded by Mr. Whitaker as probably Eocene, see 
Mem. London Basin, p. 336). 
Errors have arisen from the alteration of the glauconite in these 
beds, and from the removal of the Shells by percolating waters, an 
important discovery made independently by English and Belgian 
observers in 1876. The shells are first rendered friable and then 
completely removed by carbonated waters (occasionally leaving 
irapressions and casts), whilst the glauconite is decomposed first into 
pile-green protoxide, and finally into deep red-brown peroxide of 
1 A trivial objection is made to the use of the term Black Crag, that the deposit is 
unrepresented in England, and is tkerefore not Crag. But by use and wont “ Crag” 
is all but synonymous with Pliocene, and similar exception might he taken in every 
case wliere a foreign series bears the name of its less-developed British equivalent. 
