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TRANSACTIONS OF SECTION C. 805 
remains of the lesser Dinosauria, Labyrinthodontia, and of other vertebrata must 
be sought, and from this bed at Aust was procured the fine jaw with teeth of 
Saurichthys described by Mr. A. Smith Woodward, and several unusually perfect 
specimens obtained by the writer at Aust Cliff and Westbury-on-Severn.. 
The genus Sphenonchus, i.e., Head-defences of certain Hybodont Sharks. 
Sphenonchus hamatus, Agassiz. 
This species, already recorded in Britain from the Lias, has now been discovered 
by the author in the Rhetic bone-bed of Aust Cliff. Other specimens examined 
by him were collected by Mr. Storrie from the Lavernock bone-bed, and by Mr. T. 
Burrows in the bone-bed of the Spinney Hills. 
6. On the Skull of the South African Fossil Reptile Diademodon. 
By H. G. Srzxey, F.2.S., Professor of Geology in King’s College, London. 
Only two or three teeth have hitherto been known. The crowns are of 
mammalian type, and although referred to the Gomphodont division of the 
Theriodontia, no proof of the structure of the skull has been previously available. 
The skull now described was found at Wonderboom by Dr. Kannemeyer. It 
gives evidence of ten premolar and molar teeth,of which four are counted as 
premolars and six as molars. The molar teeth are transverse, with a type of 
crown which closely resembles Diademodon Brownii. ‘The last molar is small, 
with a narrow posterior talon. The skull is fractured, so that the cerebral region 
is lost, and the snout is lost by a vertical fracture, which passes through tbe hemi- 
spherical pits upon the pre-orbital angle at the junction of the frontal nasal and 
maxillary bones ; so that the canine teeth are not preserved. The author described 
the limits of the pre-frontal and post-frontal bones, and states that the post-frontat 
differs from that of Ornithorhynchus in its different relation to the small brain 
cavity, and in contributing to form the circular orbit of the eye. 
7. Note on examples of Current Bedding in Clays. 
By H.G. Szexey, 7. 2.S., Professor of Geology in King’s College, London. 
The author remarked that, although thin layers are defined by differences of 
colour in some slates, it is rare for bedding in the great clays to be marked unless 
by changes in mineral character. He has observed current bedding in the mottled 
clays of the Woolwich and Reading beds, and in Wealden purple clays near 
Tunbridge Wells. 
About two years since current bedding was uncovered in Messrs. Poulton's pit 
in the Reading beds at Katesgrove, near Reading. Above the current bedded 
sand, with bands of pipe-clay and fossil leaves, which occur towards the base of 
the deposit, crimson and green clays occurred in regular alternations of about 
twenty thin beds, which thickened from the west to the east. They were laid 
down in the usual curved succession of thin layers horizontally truncated above 
by the rapidity of flow of the current. The layers thickened to the west, beyond 
the sheltering bank of the deposits. Each of these beds, which was only two to 
four inches thick in the western corner of the pit in which the current bedding is 
seen, spreads over the pit as one of the nearly horizontal layers of mottled clay, 
which form the part of the section between the yellow sands below and the brown 
clay above with marine fossils. There is no evidence of the laminated structure 
being due to sand, but a few small irregular calcareous concretions, about an inch 
or two in diameter, occur in the beds of green colour. 
The second example was first observed by the Rev. T. R. R. Stebbing, F.R.S., 
at the new Recreation Ground, Tunbridge Wells, and at his request the author 
examined the section. The deposit is a purple clay of Wealden age, and either 
Weald Clay or a subordinate deposit in the Tunbridge Wells sand. It has at first 
