258 M. Desnoyers on the Chalk of the Cotentin. 



Shells. 



Baculites vertebralis 

 (2 other species . 



Hamites cylindricus . . . 

 Sea J) kites (2 species) 



Ammonites rhotomagensis 



• Gentoni . . . 



varians . . . . 



constrictus . . 



Gryphcea (small species) 



, Lamarck! 

 DeGerv.) I 



Defrance. 



Other Localities. 

 pLower chalk at Maes- 

 I tricht, Aix-la-Cha- 

 pelle, Dantzick, Tours, 

 Rouen, Nogent le Ro- 

 (_ trou, &c. 



Defrance 

 Defr. . 

 Sowerby 

 Sow. . . 



Ostrcea . . . (var. of O. vesicularis 

 named incerta by Defr.) . . . 



These four species are 



found in the lower 



chalk ( firestone ) of 



Rouen, Havre, Mor- 



taigne, and Sussex. 



rVery common in the 



J lower chalk of the de- 



J partmentsofLaSarthe, 



[_ Eure et Lior, and Orne. 



'More resembles those of 



the tufaceous chalk of 



Tours, Perigueux, Mi- 



\ rambeau, and Maes- 



I tricht, than those of 



the upper chalk of the 



Paris basin. 



Pecten 



quinquecosta 

 versicostatus , 



quadricosta , 



intextus . . . 



Tri"onia scahra ? 



Sow. 

 Defr. 



Sow. 



Br. . 



Lam. 



Common in lower chalk. 



Inoceramm Park. 



Gervillia solenoides 



Defr. 



Crania antiqua Defr. 



striata Defr. 



stellata Defr. 



L 



} 



f Greensand near Exeter, 



tandofWiltshire; Maes- 

 tricht. 

 Havre. 

 rComm.inthe lowerchalk 

 J and greensand of Rou- 

 ■\ en, Regmalard, Tours, 

 I PerteduRhone,Miram- 

 \_ beau, and Blackdown*. 



Hard chalk of the Isle 

 d'Aix ; sandstone sub- 

 ordinate to the lower 

 chalk of Longy(Orne).* 



Also in the inferior greensand of Lyme Regis, Dorset. — Trans. 



Thecidea 



