CiRC. 135. 



The Geologists will be led by Mr. Wm. Heidman, F.Ci.S., of Middleton-in- 

 Teesdale, who will conduct them to the Cronkley Pencil Mill, the strata of which 

 are classed by Messrs. Clough and Gunn as of Silurian origin, corresponding to 

 the Stockdale Shsles. After having examined the strata at the Pencil Mill the 

 party will return to the conveyances and proceed to Middleton, and inspect the 

 Basalt Quarry of Messrs. Ord & iSIaddison, of Darlington. 



The Bryologists and Naturalists, under the leadership of Mr. Richard 

 Barnes, will devote their attention to the rich moss flora of Upper Teesdale, 

 accompanying the geologists in the Hrst instance in the wagonettes. 



PROLONGATION OF EXCURSION.— Should the weather be favour- 

 able and members wishful to prolong their stay in Teesdale, Mr. Herdman and Mr. 

 Barnes will be glad to arrange for further investigation. Mr. Barnes suggests that — 

 arrangements being modifiable to suit circumstances— headquarters be at Langdon 

 Reck or High Force; one day be devoted to High Force and Cronkley, one to 

 Langdon Beck and Falcon Glints, and one to Winch Bridge and Holwick. 



Mr. Herdman would make suitable arrangements for the geologists if they will 

 write him, and he invites members to inspect his col ections of local minerals and 

 mineral spars, the best in the district. 



Mr. [ames Backhouse, F.Z.S., will probably join the party on Thursday or 

 later. 



NATURAL HISTORY WORK IN WINTER.— Although November 

 is not an ideal month for field work, there is nevertheless much to b*^ done by keen 

 investigators. If flowering plants are all over, the season is at its best for Mosses, 

 and for Lichens, while if frosts have not intervened, a number of Fungi may be 

 found. In Zoology, the conchologist may meet with many of the smaller species of 

 Mollusca, although the large thick-shelled species will have buried themselves for 

 hibernation. Vitrlna pellucida is at its l:)est in winter, and most of the slugs and 

 small land-shells creep abroad when the weather is mild. The field of investigation 

 for lepidopterists is but restricted, and mainly restricted to pupa-digging, but 

 coleopterists can do .something, and water-beetles are even to be obtained in frosty 

 weather by breaking the ice, Trapping for small Mammals is productive in winter, 

 and the movements of Birds are always to be observed. 



GEOLOGY OF UPPER TEESDALE.— Mr. William Herdman, F.G.S., 

 of Middleton-in-Teesdale, writes that the geological formations of Teesdale on the 

 Durham .side of the Tees comprise the Palaeozoic series of strata, of which the 

 Carboniferous forms a sub-division, the latter being divided into the Millstone Grit 

 and Voredale Rocks, the strata of the district comprising Arenaceous, Argillaceous 

 and Calcareous strata from the High Slate Sills to the Great Whin Sill. On the 

 mountain sides in Teesdale patches of Millstone Grit may be found; in one instance 

 at Carr's Craggs, above Newbiggin, dressed Millstone may be seen belonging this 

 series, being dressed for our northern mills, but found to be too soft, hence the 

 abandonment of the place. These strata have an inclination to the S.E., conse- 

 quently the geological student, in traversing the Tees valley to Harwood, will find 

 the strata in ascending order. On the Yorkshire side of the Tees, near the Cronk- 

 ley Scarrs, a series of strata traversed by quartz-veins and several igneous dykes 

 have been denominated as Silurian, corresponding to the Stockdale Shales. They 

 lie west on the upthrow side of the Great Burtree-Ford Fault. The Great Whin 

 Dyke, which traverses the whole length of Teesdale, can be studied to advantage at 

 Messrs. Ord & Maddison's Whinstone Quarry at ]\Iiddleton, thence at Holwick 

 .Scarrs and Falcon Glints, while minor faults have been found at Lady's Kake Mine 

 and other parts of Upper Teesdale. The celebrated water-falls of High Force and 

 Cauldron Snout contain excellent sections of Basalt, where at the latter-named 

 place it is nearly 30 fathoms thick. 



BRYOLOGY OF UPPER TEESDALE.— Mr. Richard Barnes, of Salt- 

 burn, who has paid much attention to the subject, writes that it scarcely needs 

 reiteration that the district of Upper Teesdale has been noted for some considerable 

 time for its botanical richness, and to the bryologist it offers especial charms and 

 will be found extremely interesting, since, in Yorkshire, there is no finer ground, 

 if even so fine, no ground more classic to be met with than is afforded by this 

 •district for investigation. The bryology of Upper Teesdale has been ably dealt with 



