Dr. Wright on the Lower Lias of the South of England. 401 
many fine Enaliosaurian fossils. These beds are also well exposed 
at Brockeridge and Defford in the Vale of Gloucester, and at Bin- 
ton in Warwickshire. 
Tsastrea Murchisone occurs in this zone, and Ostrea liassica is 
very characteristic of some of its lower beds. Ichthyosauri and Ple- 
siosauri of several species are found in this series ; the latter chiefly 
in the lower part. Of the two known specimens of Pl. mega- 
cephalus, one was found in these beds near Street, Somerset, and 
the other at Wilmcote, Warwickshire. 
The Ammonites Bucklandi characterizes the next higher group of 
strata, which are also known as the Lima-beds. These are well 
seen at Lyme Regis, at the Church Cliff and from the Broad Ledge 
to the shore, and yield several species of Ichthyosaurus, also Am. 
Conybeari, A. rotiformis, A. angulatus, A. Greenoughii, and A. tor- 
tilis. 
The Am. Turneri beds are next, and can also be studied at Lyme 
Regis; they have yielded three species of Ichthyosaurus. Am, semi- 
costatus and A. Bonnardi belong to this zone. 
The Am. obtusus beds succeed, between the Broad Ledge at Lyme 
and Cornstone Ledge near Charmouth; they apparently have no 
saurian fossils. 4. Brooki, A. stellaris, A. planicosta,and A. Dudres- 
sieri accompany A. obtusus. 
The next zone is that of the 4m. oxynotus, with A. bifer and A. 
lacunatus. The beds with Am. raricostatus comprise (in ascend- 
ing order) the Ammonite-bed, the Hippopodium-bed, the coral- 
band, and the Gryphza-bed. This zone is well seen near Chelten- 
ham, at Lyme, and at Robin’s Hood Bay in Yorkshire. Am. ar- 
matus, A. nodulosus, and A. Guibalianus belong to the A. raricos- 
tatus beds. 
Dr. Wright then pointed out that the Avicula contorta beds, like 
the Késsen beds, contain a fauna special to themselves, and might as 
well be classed with the Trias as with the Lias. They have a 
wide range in the South of England, South Wales, the Midland 
Counties, and the North of Ireland. After some remarks on the 
more important features of the several Ammonite-zones of the Lower 
Lias, the author concluded by remarking that, as Quenstedt and 
Oppel had observed, the Middle Lias could be similarly subdivided 
by means of the Ammonites peculiar to its several stages. 
March 14, 1860.—L. Horner, Esq., President, in the Chair. 
The following communications were read :— 
1. **On the Occurrence of Lingula Credneriin the Coal-measures 
of Durham.” By J. W. Kirkby, Esq. Communicated by 'T. David- 
son, Esq., F.G.S. 
As the Lingula Credneri of Geinitz, formerly known only in the 
Permian rocks (Lower Permian of Germany; Marlslate of Durham 
and Northumberland), has of late been found by Mr. Kirkby in the 
Coal-measures at the Ryhope Winning, near Sunderland, he offers 
this notice as of interest both as to the discovery of another species 
common to the faunze of the Carboniferous and Permian eras, and as 
illustrative of some of the physical conditions which obtained during 
