Geological Society. 495 
Mr. Williamson, in a notice on the fossil fishes of the coal-fields 
of York and Lancaster, says that these coal measures are very rich 
in Ichthyolites, which abound so much at Middleton colliery, near 
Leeds, that the workmen have given to one bed the name of fish 
coal ; they are usually in fine bituminous shale above and below the 
coal, and most frequent in the roof immediately above it, where, as 
at Burdie House, near Edinburgh, there is a thin seam of coprolitic 
matter ; they are rarely mixed with any great quantity of vegetable 
remains. In the lower measures of Lancashire they are associated 
with Goniatites and Pectens, and in the higher measures of Lan- 
cashire and Yorkshire with freshwater shells allied to Unio, and with 
Entomostraca. Exact observations as to facts of this kind are of 
inestimable importance, for it is only by careful induction from 
a sufficient number of such-like phenomena, and from similar de- 
tails as to the local distribution and condition of animal and vege- 
table remains in the marine and fluvio-marine and lacustrine depo- 
sits which compose the carboniferous series, that we shall arrive at 
a solution of the grand problem of the formation of coal. 
CRUSTACEANS. 
The Rey. T. B. Brodie has discovered in the Wealden formation 
near Dinton, in the vale of Wardour, the remains of Coleopterous 
and Hymenopterous insects, and a new genus of [sopodous Crustacea 
in the family Cymothoide. The Isopods are clustered densely to- 
gether ; the lenses in their eyes are sometimes preserved ; there are 
also traces of legs, but of no antenne. With them he has found a 
large species of Cypris. The insects are chiefly small Coleoptera ; 
there are several species of Dipterous, and one Homopterous insect, 
and the wing of a Libellula. Mr. Brodie’s discovery is the first yet 
made of insects in the Wealden formation, and also the first example, 
in a secondary formation, of Isopods that approximate in form to 
the Trilobites of the Transition series. 
ICHNOLOGY. 
About twelve years ago we witnessed the creation of a new de- 
partment in geological investigations, viz. the science of Ichnology, 
founded on the evidence of footsteps made by the feet of animals 
upon the ancient strata of the earth ; this new method commenced 
with the recognition of the footmarks of reptiles on the New Red 
Sandstone near Dumfries, and not long after (1834) was followed 
by most curious and unexpected discoveries in Saxony and Ame- 
rica. The Chirotherium of Hessberg and Ornithichnites of Con- 
necticut were among its early results. Our own country has during 
the last two years been abundantly productive of similar appearances 
in many localities. 
In recent excavations for making a dock at Pembray, near 
Llanelly, in Pembrokeshire, tracks of deer and of large oxen have 
been found on clay subjacent to a bed of peat, the lower peat being 
moulded into the footsteps ; similar impressions were also found upon 
the upper surface of the peat beneath a bed of silt, and bones both of 
