396 Dr, A. Morley Davies—Zones of the 
Erymnoceras reginaldi (Morris) in the upper part of the section ; but 
the most typical members of the faunaare quite unknown in England. 
Possibly, two zones should be recognized, only the lower (coronatum 
zone) being found in England. 
3. Upper ornatum or duncani zone.—This is the zone with 
pyritized ammonites, mainly Cosmoceras spp. and Perisphinctes spp. 
It is seen at Summertown (Oxford) and at many pits in the Peter- 
borough district, e.g. Eye Green. In Bucks and Beds I have not yet 
found it, except doubtfully at Woburn Sands. ‘The total thickness of 
the ‘‘ ornatum zones’’ is very considerable, and several minor divisions 
might be distinguished, corresponding generally to those recognized 
by Judd in the Peterborough district.!. The Wootton Pillinge district 
seems to offer the best opportunity of working these out. 
4. Athleta zone.—The clays which I place in this zone are 
deficient in ammonites. They contain <Aulacothyris bernardina 
(VOrbigny) and abundant Gryphee which may be identical with 
G. bilobata, J. de C. Sowerby, though after examining a very large 
number of Upper Jurassic Gryphee I hesitate to give a definite 
specific name to any. In the two places where I have seen these 
beds exposed—Ludgershall railway cutting and Eastman’s brick- 
works, Woburn Green—they underlie the well-marked renggeri zone. 
At my last visit to Woburn Green (in July, 1914) I saw one 
ammonite that suggested that the section penetrated down to the 
duncani zone below, but I was too much occupied with the higher 
beds (usually quite inaccessible, but then most fortunately measurable 
in detail) to have any time to examine fully the lower part. Nowhere 
else have I seen any evidence of the superposition of this zone on any 
other. 
5. Renggert zone. — This zone was well exposed during the 
excavation of the Ludgershall railway cutting (Great Western 
Railway, direct Birmingham line). It is also shown in the upper 
part of the Woburn Sands brickworks, at a small excavation at 
Aspley Guise (opposite the first houses up the hill from the railway 
halt), and at the brickfield at Sandy, Beds. From the large 
collection of fossils from Ludgershall it is possible to state that 
the fauna is essentially that of Liesberg in the Bernese Jura,’ with 
certain interesting minor differences :— 
(1) The absence of Phylloceras. It is well known that this 
Mediterranean genus only occurs sporadically in Central Europe 
and Britain, and less frequently in the latter province than in the 
former. No Phylloceras is known in Britain above the Upper Lias. 
(2) The much greater abundance and variety of forms of 
Quenstedticeras, indicating boreal affinities. 
(3) The Oppelid Zaramelliceras episcopale is represented in the 
Bernese Jura by its typical form only ; in the Ledonian Jura (farther 
south) it is accompanied by the thicker variety globoswm, but at 
Ludgershall thinner varieties predominate. 
(4) Cosmoceratids are not found in the Bernese and Ledonian 
areas; in more northern areas the last species of this family still 
1 J. W. Judd, Geology of Rutland (Mem. Geol. Surv.), 1875, pp. 232-6. 
2 P. de Loriol, Mém. Soc. Pal. Suisse, xxv—xxvii, 1898-1900. 
