78 MR. B. THOMPSON ON THE GEOLOGY OE THE [Feb. 1 899, 



about 6 feet in depth only, I found Ammonites ibex and A. Valdani 

 fairly abundant, whereas no part of the slope higher up yielded 

 any. Some of this material had recently been tipped between 

 60 miles 52 chains and 61 miles 4 chains, and from this I obtained 

 other fossils recorded as belonging to the ibex-zonei. 



Mr. H. B. Woodward says ^ : — ' The late Prof. A. H. Green, who 

 had previously examined the cuttings from Nethercote to Charwelton, 

 sent to the Museum of Practical Geology a number of fossils which 

 he had obtained from an excavation in the low ground south-east of 

 Nethercote. These were identified by Mr. G. Sharman & Mr. E. T. 

 Newton, as follows : — 



Ammonites Maugencdi, d'Orb. 



Belemnites. 



Avicula incsquivalvis, Sow. 



Cardinia concinna, Stutcbb. 



C. Listen, Sow. 



Gryphcea cymbium, Lam. 



Lima Hermanni, Voltz. 



Ostrea. 



Tecten (Bqualis, Queust. 



P. (squivalvis, Sow. 



P. lunularis, Eoem. 



Plicatula spinosa. Sow. 



The assemblage is interesting as indicative of the zone of Ammo- 

 nites ibex, which is rarely to be recognized in this country.' 



It may be noted that the ibex-zone has for a long time been well 

 exposed at Braunston. 



It would thus appear that the ibex-zone is mostly below the 

 cutting for the railway. 



{k) Zone of Ammonites Henleyi (fi^s. 4 & 5_, pp. 74 & 7Q). 



A large portion of the cutting just described, above the lowest 

 12 to 6 feet, according to the position north or south, in all 

 probability belongs to the Henleyi-zone. It consists of a stiff blue 

 clay not appreciably different from that of the ibex-zone below. 

 Here and there were nodules, some very large, a few ferruginous or 

 ochreous, and as a rule very unfossiliferous, like the clay. The 

 only fossils found on the sloped bank, and these rather low down, 

 were Ammonites striatus and Inoceramns ventrioosus, but I did not 

 examine the section well. A few other fossils were found where 

 the material was tipped. 



The cutting from 59 miles 57 chains to the fault, 60 miles 9 chains 

 (fig. 5, p. 76), is almost all Henleyi-zone^ with the exception of a 

 little Boulder Clay. The only fossils that I collected from here were 

 two young specimens of Ammonites Henleyi, Sow. (=A. latcecosta, 

 Sow., according to Wright ^), showing remarkably well the gradual 

 evolution of A. Henleyi from a cajoricornus-like form. 



Another cutting, extending from 61 miles 30 chains to about 

 61 miles 54 chains, appears to expose the Henleyi-zone. The upper 

 part of this cutting is Boulder Clay and Drift Sand-and-Gravel, 

 but the lower consists of a light-blue clay with ironstone-concretions, 

 and no fossils that I could discover ; it is therefore almost certainly 

 not capricornus-zone, nor ibex-zone. 



' Geol. Mag. 1897, p. 98. 



'^ ' Lias Ammonites/ Palseont. Soc. Monogr. (1878-1886) pp. 36D-368. 



