134 Dr Boue’s Geological Comparative View of the 
Spain. As in other countries, it contains beds of micaceous spe- 
cular iron-ore (Bastenes), also gypsum ( Pouillon ), crystals of 
ferruginous quartz (Hyacinthe de Compostella), and arragon- 
ites, as in Spain. Some beds of limestone, either compact or 
identical with the Hartz roestone , are seen towards the upper 
part of the formation (near Dax), and indicate the approach of the 
second ficetz limestone or shell limestone (muschelkalk), which 
is compact, and to be seen here and there under the Jura lime- 
stone. The third floetz sandstone , or quadersandstein , forms also 
an extensive tract along the whole course of the Pyrenees : it 
is always white or grey, more or less fine grained, marly,, and 
with mica, and contains vegetable remains and marine fossils, 
together with traces of lignite and hydrate of iron, or brown 
iron-ore. The Jura limestone lies over it, and forms, especially 
at both extremities of the chain, an extensive tract of country. 
Some traces of gryphite limestone or lias , magnesian Jura lime- 
stone, and compact limestone , with few beds of oolite, compose 
this deposit, in the lower part of which there are traces of lig- 
nite (Les Corbieres). 
Of all these floetz formations, the Jura limestone only reappears 
in the northern part of the great south-western secondary basin 
of France, and covers all the others, excepting a small patch of 
zeclistein, and perhaps of shell-limestone (muschelkalk), near 
Figeai and that neighbourhood. All the northern part of Pe- 
rigord, the southern part of Poitou and the Saintonge, are Jura 
limestone. Here and there some masses of gypsum belonging per- 
haps to the red marl, make their appearance (Rochefort). In 
the eastern part, the lias and compact limestone abound ; in the 
western, the compact newer limestone , the shelly limestone , and 
the coral rag or calcaire a polypiers (La Rochelle). The enu- 
meration of the beautiful petrifactions of this deposit would not 
be consistent with the limited nature of this communication : 
they are various and characteristic ; Diceras, Ammonites, Tere- 
bratulse, Cerithia, &c. Upon the Jura deposit there lie upon 
both sides of the basin, the iron and green sand formation, and 
the chalk ; the first deposit is most beautifully seen in the Saint- 
onge, and in the departments des Landes. Its component parts 
are sand, sandstone, fine and coarse , indurated sandstone , used 
for pavements, ferruginous sandstone , beds of clay, short beds 
