1 8 thf: eocene beds 



The fauna of this horizon is exceedingly varied, Nautilus 

 Lainarcki and N. umbilicaris are not uncommon at Pont-St.- 

 Maxence and Vaugirard, while the fine r.pecies above men- 

 tioned and Cordis suhpedunculus are specially characteristic. 



The ''Banc a Verrains." This horizon is generally formed by 

 a very fossiliferous limestone called in the quarries near Paris 

 " Saint- Jacques.'" At Issy, Gentilly, Montrouge and elsewhere 

 it furnishes stone of excellent quality, only slightly inferior to the 

 Pierre St.-Leii. The fauna is most prolific and varied, especially 

 where the beds are in a calcareous sand, as at Damery, Fleury- 

 la-Riviere, Chamery, Parnes, Chaussy, Grignon, Chaumont, 

 Courtagnon and elsewhere ; the fossils are then perfecdy pre- 

 served, even retaining colour markings in some instances. This 

 may be particularly noticed with Volutilithes spinosus, the shell of 

 which is often marked with orange-coloured bands. Among the 

 typical fossils of this horizon, Cerithium giganieiim is the most 

 important ; the casts of this gastropod are called " Verrains" and 

 from their occurrence the bed is named. Other forms are 

 Turritella inibricataria, T. sulcifera. T. carinifei-a, Volutilithes 

 cithara, Mesalia intermedia., M. miilti sulcata, Cerithium serratuin, 

 Axi'iina pulvinata, Crassatellaplumbea ; Cephalopoda as Belosepia 

 sepioidea; Echinoidea such as Echinolampas, Breynella, Fygorhyn- 

 chus and Hemiaster. 



Middle Calcaire Grossier (or Calcaire Grossier with 

 Miliola). Where most fully developed, the Middle Calcaire 

 Grossier may be sub-divided into the five horizons indicated in the 

 table of classification, forming two groups, the lower called 

 Vergeles or Lambourdes,\ and the central part Banc Royal. 



The Vergeles are yellowish-white limestones often marked with 

 iron veins, and where hard, form good building stones, as at 

 Chantilly, Carrie'-e Saint-Denis and Nanterre; they are very well 

 developed in the department of Oise. 



The Banc Royal furnishes large and very good building 

 stones, worked among other localities at Mery-sur-Oise, Neuilly, 

 Montrouge and Gentilly. 



Taken as a whole the Middle Calcaire Grossier is an accumu- 

 lation of thin incoherent beds of sandy Calcaire Grossier with 

 freestone beds developed in places, where it receives the distinc- 

 tive names already described. The Fauna here, as in the Lower 

 Calcaire Grossier, is exceedingly rich and interesting ; Vertebrata 

 are represented by Hemirhynchus Deshayesi and other species, 

 particularly at Puteaux (Seine) ; while a rich Flora of marine 

 or brackish water plants, such as Culmites, Phyllites multinervis 

 and Equis.'tum deperditum, has been described from various 

 localities, as La Glaciere, Montsouris, &c. The MoUusca are well 

 represented and well preserved, as at Grignon, Parnes, Mouchy 

 and other rich localities. Lithocardium aviculare, Cerithium 



* Lainliourdes = !^oh stone. 



