63 Geological Society. 
Part I].—Notes on the Ammonites. By Leonard Frank Spath, 
DSe.3 F:G.S: 
The paleontological part contains descriptions of the genera of 
ammonites found in the Shales-with-Beef, and remarks on their 
classification and phylogeny. The following new genera are 
proposed :—Pararnioceras; genotype, the species to which spe- 
cimen No, 2713, Coll. W. D. L., belongs, identified by the Author 
with Ammonites alcinoé Reynés (1879, pl. xxiu, fig. 10). 
Sulciferites; genotype, the species to which specimen Brit. 
Mus. C. 16416 belongs, identified by the Author as Ammonites 
sulcatus J. Buckman (Pal. Univ. 1904, No. 39, fig. 2). 
Part I1L.—Petrological Notes. By William Alfred Richardson, 
Mise: F.G:S. 
The development, in some beds, of lamination by weathering is 
described, and the presence of barytes recorded. A study of the 
concretions leads to the following conclusions as to the sedimentary 
history of the beds :— 
(1) During sedimentation, caleium carbonate gradually accu- 
mulated in solution in the waterlogged deposit. 
(2) During the initial stages of desiccation and draining, a 
system of limestones and calcareous nodules was precipitated 
r hy thinically. 
(3) During the later stages of desiccation, veins of fibrous 
calcite were “deposited at levels of low pressure. Cone-in-cone 
structure, found in these veins, is due to pressure operating during 
growth, partly by spreading the growing crystals and partly by 
setting up planes of shearing closely parallel to the cleavage of 
the fibres. 
(4) The remaining solutions of calcium carbonate were ulti- 
mately deposited as a cementing material, on the final drying of 
the deposit. 
January 18th, 1922.—Mr. R. D. Oldhan, F.R.S., 
President, in the Chair. 
The following communications were read :— 
1. ‘Jurassic Plants from Ceylon.’ By Prof. Albert Ghanied 
Seward, Se.D., F.R.S., F.G.S., and R. E. Holttum, B.A. 
The collection of plant- aes described by the Authors 
was obtained by Mr. E. J. Wayland, from a shale resting upon 
Archean rocks at Tabbowa in the Neck Western Province of 
Ceylon. ‘These are the first fossil plants recorded from that island. 
Of the six species determined five appear to be identical with 
plants deseribed by Feistmantel from Jurassic rocks on the 
Madras coast; these are :— 
Cladophlebis reversa (Feistmantel); ©. denticulata (Bron- 
eniart). 
Teniopteris spatulata (McClellan). 
Araucarites cutchensis (Feistmantel). 
