GREAT OOLITE : FULLONIAK 
231 
FlTLLONIAN OB FULLER S EARTH FOSSILS. 
FIG. 63. FIG. 65 
FIG. 66. 
FIG. 64 
FIG. 67. 
FIG. 63. Ammonites arbustigerus, d'Orb. J. 
,, 64. subcontractus, Mor. & Lye. 4- 
,, 65. Ostrea acuminata, Sow. Nat. size. 
,, 66. Waldbeimia ornitb.ocepb.ala, Sow. Nat. size. 
,, 67. Bbyncbonella varians, Scbloth. If. 
The Ammonites (A. subcontractus and A. viator) are decidedly 
Bathonian, and so generally do we find the former species in the 
Fuller's Earth Rock, it might be termed the zone of A. sub- 
contractus. It is however more convenient to take A. arbustigerus 
as the zonal index for the Great Oolite Series, from the Fuller's 
Earth to the Forest Marble. 
The Gasteropods, as a rule, are too poorly preserved to admit of 
specific identification, but the genera belong as much to the 
Inferior Oolite as to the Great Oolite.* 
The Lamellibranchs include 43 species found also in the 
Great Oolite, and 30 in the Inferior Oolite, many of them 
passing upwards from the one formation into the other. Avicula 
* The species are included with those from the Great Oolite in the Catalogue of 
British Jurassic Gasteropoda by Hudleston and Wilson; see also Hudleston, 
Gasteropoda of Inferior Oolite, p. 19. 
