UPPER LIAS FOSSILS. 24? 
Locally the zones have been further subdivided, and these 
minor zones or sub-zones will be mentioned in due course. 
The fossils of the Upper Lias include species of Ichthyosaurus, 
Pelagosaurus, and Steneosaurus ; but Saurian remains are by no 
means so abundant in the area under consideration as they are in 
Yorkshire. More important are the remains of the Fishes, 
especially Leptolepis and Pachycormus. Otolites have also been 
obtained. 
Of Mollusca, Ammonites and Belemnites are plentiful thi'ough- 
out the formation, and species of Nautilus are not uncommon. 
The Gasteropods include Amberleya (JSucyclus), Cerithium, 
Euomphalus (!), Plcurotomaria, Trochus, Turbo, and Turritella. 
Dentalium is also found. Among the Lamellibranchs we find 
Astarte, Gucullcea, Gresslya, Inoceramus, Leda, Lima, Monotis, 
Nucula, Ostrea, Pecten, Pleuromya, Posidonomya, Thracia, and 
Trigonio. 
Brachiopoda are far less abundant than in the Middle Lias : 
the species include Discina, Lept&na, Lingala, Rhynchonella, 
Waldheimia and Thecidium. Polyzoa are exceedingly rare. 
The Crustacea include Eryon, Palinurina, Penceus, and some 
Ostracods. The Insects can only be mentioned, as the names 
require revision, but they include the Dragon-fly, Libellula. Of 
Annelides, Ditrupa and Serpula are fairly abundant. Echino- 
derms, with the exception of Pentacrinus are rare, but they 
include Acrosalenia, Cidaris, and Hemipedina. Corals also are 
rare, but Thecocyathus and Trochocyathus have been recorded. 
A number of Foraminifera have been obtained.t Lignite is found, 
but no plant-remains of recognizable species have been recorded. 
In Yorkshire the lowest zone of the Upper Lias is known 
generally as that of Ammonites annulatus ; but it was grouped 
with the Middle Lias by Messrs. Tate and Blake, on account of 
its yielding more .Middle Lias than Upper Lias species; and 
among these they record A. margaritatus. As suggested by Mr. 
Walford (see p. 228) the Transition Bed of the country around 
Banbury, &c. may in point of age be equivalent to this zone, for 
it yields some of the same Gasteropods and other fossils. % Mr B. 
Thompson would also include in the same zone portions of the 
Lepta>na-beds described by Charles Moore. In this southern 
part of England there was evidently a paucity of sediment as 
compared with the Yorkshire deposits, at the junction of Middle 
and Upper Lias. 
At the bottom of the Upper Lias in the area from Somerset- 
shire to Lincolnshire, there occur at intervals certain shales and 
limestones known as the Fish and Insect Beds. Attention was 
first called to these beds in Gloucestershire by the Rev. P. B. 
Brodie, and they were subsequently recognized in Somersetshire 
* Yorkshire Lias, p. 171. 
f See W. D. Crick and C. D. Sherborn, Journ. Northamptonsh. ]Nat. Hist Soc., 
vol. vii. p. 67. 
J Fox-Strangways, Jurassic Rocks of Yorkshire, vol. i., p. 126. 
