The Geologids' Association. 333 



Llandeilo Limestone =Lower Bala. 



Bicranograptus shales =Lowerand Middle Bala. 



Eobeston Watben Limestone =Bala Limestone. 



Trinucleiis-seticornis beds =:Upper Bala. 



Conglomerate 1 — L M H'll 



Fossiliferous Lower Llandovery beds j ^ ' 



In conclusion the authors notice two points which require further 

 elucidation. The first is the separation of the Eobeston Wathen 

 and Sholeshook limestone. This is made on palfeontological and 

 lithological grounds, as the whole thickness of the two limestones 

 had nowhere been met with in the same section. The second is the 

 relationship of the conglomerate to the fossiliferous Lower Llandovery 

 beds. In the only place where the two appear in justaposition the 

 conglomerate series appear to underlie the fossiliferous Llandovery 

 beds ; this the authors explained by a faulted overfold. These 

 difficulties do not, however, prevent the authors from hoping that the 

 sequence they have established will be of use in assisting to deter- 

 mine the character of the very remarkable folds by which the district 

 lias been affected. 



3. " On certain Fossiliferous Nodules and Fragments of Hsematite 

 (sometimes Magnetite) from the (so-called) Permian Breccias of Lei- 

 cestershire and South Derbyshire." By W. S. Gresley, Esq., F.G.S. 

 In this paper the author described certain pebbles of haematite 

 and magnetite which occur in the so-called Permian breccias on the 

 western margin of the Ashby-de-la-Zouch Coal-field. These pebbles, 

 which are largely collected for sale and used as "burnishers," vary 

 in size from a diameter of iV inch to the size of a man's fist. They 

 present many varieties of form, have sometimes an agate-like struc- 

 ture, and occasionally exhibit well-marked magnetic polarity. Some- 

 times they show grooving and striation resembling those produced 

 by ice-action, while at other times they seem to have been crushed 

 and recemented. Many of these pebbles contain fossils of various 

 kinds, chiefly plant- and insect-remains, but with a few of Annelids, 

 Mollusca and Fish. All the fossils are of Carboniferous age. 



From the consideration of all the facts detailed in the paper, the 

 author concluded that these nodules were originally composed of 

 clay ironstone, and that they were derived from Carboniferous strata. 

 He considered that the pseudomorphic action by which they have 

 acquired their present composition must have taken place in situ 

 since their inclusion in the breccia. 



HI. — The Geologists' Association. 



At a meeting held at University College, on the 5th June last, 

 Mr. Herbert Goss, F.L.S., F.G.S. , etc., read a paper " On Some 

 recently-discovered Insecta and Arachnida from Carboniferous and 

 Silurian Rocks." After remarking on the great number of Palaeozoic 

 Insects lately discovered, and calling attention to the recent investi- 

 gations and writings on the subject of M. Charles Brongniart, Mr. 

 Scudder, Dr. Deichmiiller, Dr. Dohrn, Dr. Fritsch, Dr. Eugen Geinitz, 



