396 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar, 23, 
go far to establish a broad line of demarcation between the Lower 
and Middle Lias. 
The species enumerated in Table I. (p. 397) from the zones of A. 
oxynotus and A. raricostatus have occurred at Cheltenham, with the 
following exceptions, Bel. cacavatus and B. elegans (Yorkshire), and 
Montlivaltia mucronata, M. mammiformis, and M. radiata (Fenny 
Compton), Those in. Table II. (p. 398) have chiefly been obtained 
from near Cheltenham and at Aston Magna; the species recorded by 
Drs. Oppel and Wright, Mr. Day, and Prof. Phillips, from the zone of 
Ammonites Jamesont in Yorkshire and Dorsetshire, are introduced. 
At Cheltenham the zone of Ammonites Jamesoni is exposed in 
the clay-pits by the Leckhampton Road; it consists of a mass of 
blue shaly clay with a few thin bands of compacted shells. With 
the exception of Ammonites ibex, A. Valdani, A. , Henley, the Belem- 
nites, and Inoceram#, the fossils are of small size, but most of the 
species goumerated: occur in great numbers. The most abundant 
speciesAre Ammonites Valdani, Belemnites clavatus, B. umbilicatus, 
B. ovyconus, Dentalium minimum, Cerithium Slatteri, Chemnitzia 
hassica, C. Blainvillet, Turbo admirandus, Nucula cordata, Leda 
Galatea, Arca Stricklandi, Pentacrinus basaltiformis, Waldheimia 
numismalis. The totality of the species correlates these beds with 
the Belemnite schist or Numismalis-beds of Hanover, Wirtemberg, 
and France, the most complete list of fossils from which is that 
given by Schlonbach*. He records, eliminating synonyms, seyenty- 
five species from this zone as developed in the north of Germany ; of 
these, thirty-nine are peculiar, thirty-three pass to the zone above, six 
are found in the Lower Lias, and thirty-six occur in beds of the 
same horizon in England. 
The species recorded from Aston Magna were obtained by Mr. 
Thomas Slatter in the railway-cutting near that village: the exact 
relation of the bed yielding the fossils was not ascertained ; but that 
gentleman informs me that it is a soft blue clay underlying five or 
six feet of blue shaly clay, literally filled with broken pieces of 
Spiriferina verrucosa and Belemnites. The specific identity of the 
greater number of the fossils from this section with those from the 
zone of Ammonites Jamesoni at Cheltenham requires the Aston beds 
to be referred to that horizon. 
From Table I. I deduce that of the fifty species recorded from 
the zones of Ammonites raricostatus and .A. owynotus, chiefly in the 
neighbourhood of Cheltenham, eight pass to the zone of A. Jamesoni, 
whilst thir teen occur in lower horizons, and twenty-nine are peculiar 
to these horizons in England. 
Table II. records one hundred and fifteen species in the zone of 
Ammonites Jamesoni, sixty of which pass to higher zones, whilst 
eleven make their Siete appearance in the Lower Lias. Of the species 
common to the Lower and Middle Lias, five have been enumerated 
in the first table, so that there are fourteen species in common to 
the two formations. 
But other species of the Lower Lias, not given in the above tables, 
reappear in higher stages of the Middle Lias. Such migrated species 
* Deutsch, geol. Ges, vol. xv. 1863, 
