68 FOREIGN RELATIONS OF THE 



water formations, we naturally look for their best marked repre- 

 sentative beds to occur along other parts of the old shore line. In 

 the Ardennes district these old coast deposits are again well de- 

 veloped, and in some places they appear actually to be extremely 

 similar to our Ironsand series. They have been thoroughly worked 

 out by M. Barrois 1 , who refers them principally to the Mammillaris 

 zone 2 , and the Upper Neocomian or Aptien. 



In the comparison of the Upware and Brickhill fossil species 

 with these beds we find that (1) they shew but little affinity to the 

 Mammillaris zone, just as we found in England. The Upware bed 

 does not belong to this zone, but still there are some eight or ten 

 species common to the two deposits, including (see Barrois, p. 271) 

 Terebratula capillata, d'Arch.; Terebratula Moutoniana, d'Arch.; 

 and Waldheimia Juddii, Walker. 



(2) A far more important list of species (more than 20) links 

 the Upware bed with the Lower Aptien clays and sands of the 

 Ardennes. These include Pecten Dutemplei, d'Orb. ; Spondylus 

 Roemeri, Desh.; Verticillites anastomosans, Mantell; Elasmostoma 

 acutimargo, Roemer; Elasmostoma pezisa, Goldf; Peronella fur- 

 cata, Goldf.; Terebratula depressa, Lam.; Terebratula Moutoniana, 

 d'Arch.; Waldheimia pseudojurensis, Leym.; and Waldheimia ta- 

 marindus var. magna, Walker. 



Several of these are very characteristic of our Ironsand and 

 Phosphatic series. Moreover the lithological resemblances are 

 also, according to M. Barrois, very close, for that gentleman writes 

 (1. c., p. 257): "J'ai e'te' frappe" de 1'analogie du Gompholite de 

 Blangy avec le Farringdon Gravel; 1'aspect des couches est le 

 meme, les caracteres de leurs faunes sont identiques; il y a enfin 

 a Blangy des formes connues (Verticillites anastomosans, Terebra- 

 tella truncata, Cidaris Farringdonensis} qui sont si caracteVistiques 

 du gisement du Farringdon, que je crois que tons les gdologues 

 qui compareront ces deux localite's n'he'siteront pas & les identifier 

 malgre' leur e'loignement et leur isolement;" and I have no hesita- 

 tion in adopting his views that the lower Aptien beds of the 



1 "MSmoire sur le terrain cre'tace' des Ardennes et des regions voisines, par le 

 Dr Charles Barrois," Annales de la Socilte Gtologique du Nord, tome v., page 227. 

 Lille, 187778. 



2 By English geologists the Mammillaris zone is usually placed in the Folkestone 

 series as the uppermost bed of the Lower Greensand, but on the continent it is put 

 into the Gault. 



