LECKENBY — NOTE ON THE SPEETON OLAY OF YORKSHIRE. 11 
17. Blue clay with Ammonites and Belemiiites as uuder : — 
Ammonites rotula. 
venushis. 
concimius. 
(variety 
with coarser radii). 
Belernnites j'aculum. 
(a short thick species). 
Thickness 12 feet. 
18. A band of clay without fossils except traces of decomposed 
Hamites 8 feet. 
19. The remarkable " Astacus ornatus bed," with innumerable 
nodules, each containing an Astacus (Astams (?) ornatus, Ph.). 3 feet. 
20. Strong clay without fossils 15 feet. 
21. Another thick deposit containing no fossils except the outer 
whorl of a large undescribed Ammonite 50 feet. 
22. Another thick bed of stratified clay, forming the Cliff ; the 
lowest portion full of crushed imperfect bivalves {Mi/a depressa) ; 
through its centre runs a band of cement-stone, containing a large 
smooth Ammonite, and fragments of Hamites maximus ; and imme- 
diately above the cement-stone-band is a seam of soft stone with 
Vermicularia Sowerhii 50 feet. 
The cement-stone yields — 
Hamites Banksii (Bean). 
Ammonites fissicostatus. 
Auricula. 
Plagiostoma. 
The occurrence of Vermicularia Soiverhii and Aminonites fissicostatus, 
which so nearly resembles A. Deshayesi of the Greensand of the Isle of 
Wight as to be almost inseparable, would seem to refer the upper por- 
tion of these beds to the Neocomian era ; while so characteristic an 
Ammonite as A. biplex in the lowest beds would with equal certainty 
refer the lower ones to the era of the Kimmeridge Clay. Between 
them we have probably the representatives of the Gault in the Hamite- 
yielding beds, while we are puzzled to account for the presence of 
such true Oxfordian forms as the coi'onated Ammonites, A. quadrlfidus 
and A. caveatus, although perhaps these are not more erratic than A. 
Parkinsoni, which, while it characterizes the Inferior Oolite of the 
south, occurs in the Grey Limestone at Scarboroiigh, not seventy 
feet below the Cornbrash. 
