1857.] BUCKMAN OOLITES. 105 



Ammonites *Humphresianus, Sow. (?). Fairford. 

 „ * Jurensis (?) Zieten Dry Lease. 



With even this list of Ammonites before us, we should hesitate in 

 stating that the bed they came from must be Inferior Oolite ; whilst 

 it would be just as unreasonable to demand that the Cornbrash, with 

 its intermediate member the Great Oolite, should henceforth be added 

 to the Inferior Oolite. 



Again, we must not always conclude a difference of horizon on 

 account merely of a change in species, especially if we reflect how 

 loose is the definition of a species, and how unsettled are opinions 

 concerning their identification ; but we must take a more enlarged 

 view of the subject, and not pin our faith too much upon the labels 

 of either Cephalopoda or Brachiopoda, or Mollusca generally : we are 

 bound to take into consideration all the circumstances of lithological 

 structure, stratigraphical position, and every family of included fossils. 

 As the section of Nailsworth has been referred to, it may be well 

 to state that here, at the base of the sands, is a bed of sandy 

 Oolite, which, though small, as is the opening by the road-side, has 

 yet furnished a good list of fossils, which is constantly being added 

 to ; the following, however, will afford an analysis of their groups, 

 as worked out by the assistance of Mr. Lycett during my last 

 visit : — 



Species. Common to Lias. 



Ammonitidse 2 . . 



Belemnitidse 1 . . 1 



Gasteropoda 4 . . 



„ new forms .... 1 . . 



Lamellibranchiata 15 . . 3 



„ new forms .... 5 . . 



Brachiopoda 2 . . 1 



rn 



Total 30 . . 5 



Here, then, as we proceed downwards in these sands, the propor- 

 tion of Liassic to Oolitic forms decreases ; but, once pass the sand 

 boundary-line, and all the species are Liassic ; and I still contend 

 that Dr. Wright's most respectable witnesses to his new theory have 

 been taken from the undisputed Lias. 



In this state of the evidence, then, I cannot subscribe to the new 

 views ; but, on the contrary, rather incline to the belief that even the 

 sands belong to the true Oolitic horizon. They mark, where they 

 occur, a great change in physical conditions, and, as a consequence, 

 have induced a corresponding impression upon the included fauna, 

 both as regards general appearance and specific details, — two 

 points to be kept distinct, as the same fossil species from different 

 mineral matrices will have very different aspects ; and again, as far 

 as species are concerned, the list from the Cephalopoda-bed has 



* These two species are stated with some doubt, as the specimens are very 

 imperfect. The list of Ammonites is being added to constantly, and will be found 

 more in detail in its place in the Cornbrash. 



