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coarser shale, and consist chiefly of large teeth and vertebre of a 
species of Holoptychus and rays of Gyracanthus. 
The yard coal shale is still less fruitful than either of the other 
seams, and has yielded only a few small teeth of Holoptychus, Cte- 
noptychus, and some other unimportant fragments. It has however 
been very slightly examined. 
On comparing these fossils with the Ichthyolites which he has 
found in Lancashire, the author has ascertained that many are iden- 
tical, but that others differ. The species of Diplodus, Ctenoptychus, 
Megalicthys, Gyracanthus, one of Holoptychus ? and Platysomus ? 
exactly correspond in each district. In the Lancashire field he has 
found remains of Ctenoptychus apicalis and C. denticulatus, which he 
has not noticed in the Yorkshire; and he is inclined to think, that 
the former field is characterized, if there be a difference, by the 
greater prevalence of Lepidoid fishes, and the latter by those of the 
Sauroid family. 
The Ichthyolites occur chiefly in highly bituminous shales, with 
the exception of the Ardwick limestone, and most abundantly where 
it is finely grained. They are rarely associated with any quantity of 
vegetable remains; and this disposition of the two kingdoms, Mr. 
Williamson is of opinion may assist in determining the conditions 
under which the coal-measures were deposited. The Ichthyolites 
also are in general more common in the roof than the floor of the 
coal; but in the cannel-seams of Wigan in Lancashire, and in the 
thin seams connected with the limestones at Ardwick, they are most 
abundant in the floor. They are rarely found in the coal itself, and 
the instances in which they have been met with in that position by 
the author, have been chiefly in the Middleton colliery. 
The manner in which Ichthyolites are associated with other re- 
mains, Mr. Williamson states, is well worthy of attention. At Bur- 
diehouse they occur in the midst of Unios, Cyprides, and Microconchus 
carbonarius ; at Colebrook Dale, with species of Orbicula, Trochus, 
Nautilus, Orthoceras, and Conularia; in the lower measures of Lan- 
cashire in beds nearly associated with those containing Gonzatiies 
Listeri and Pecten papyraceus ; in the higher measures of Lancashire 
and in Yorkshire, with Unionidee and Entomostraca; at Middleton, 
with Lingule; at the top of the series in Lancashire and Derbyshire, 
with Mytili. 
In conclusion, the author acknowledges his obligations to Mr. 
Thomas Seale of Leeds, and to Mr, Embleton, the manager of the 
Middleton collieries. 
A paper was last read, entitled, ‘‘ A brief notice of the Geology 
around the shores of Waterford Haven,” by Major Austin. 
In this memoir, the author describes topographically the geology of 
Waterford Haven, commencing at Bag and Bun Head, near its east- 
ern entrance, and proceeding around its shores terminates his ac- 
count at Ballymacaw. The formations of which the district consists 
are, 1, limestone; 2. aconglomerate; 3. clay-slate; 4. various trap- 
rocks; and 5. alluvium. 
