ANNIVERSARY ADDRESS OF THE PRESIDENT. 



235 



S. reticulata, M'Coj r ; S. depressa, Dalm. ; S. rhomboidalis, Wahl. ; 

 S. antiquata, Sow. ; Chonetes sp. ; Leptcena sericea, Sow. ; L. trans- 

 versalis, Dalm. Conchifera : Ctenodonta sp. ; Pterincea sp. ; 

 Mytilus mytilimeris, Conr. ; Orthonota rigida, Sow. Gasteropoda : 

 EuompJialus rugosus, Sow. Cephalopoda : Orthoceras attenuaturn, 

 Sow. ; 0. angxdatum, Wahl. ; and Orthoceras sp. 



These five borings within the metropolitan area are of infinite 

 scientific as well as economic value; and in addition the equally 

 important trials at Burford due west of Ware, and that of North- 

 ampton N.W. of London, open up important questions as to the 

 deeply-seated structure of the triangular area having W T are and 

 Burford at its base and Northampton at its apex. Have we within 

 the rolls and folds of the Devonian rocks as they strike across 

 England between latitude 51° and 52° any still undiscovered coal- 

 tracts ? is the Bristol coal-field repeated to the east and N.E. to 

 Burford, with the underlying Devonian in place to the south-east ? 

 It would appear so when we regard the bearing and strike of the 

 older rocks towards the continent. The geological importance and 

 interest of these borings is their revelation to us of the old Palaeo- 

 zoic land-surfaces, whether coast-lines or tablelands, theoretically 

 enabling us to reconstruct the physiography of those land-masses, 

 concealed, yet connected to now exposed areas, whether British, 

 European, or even American. 



February 23, 1881. 



Robert Etheridge, Esq., E.R.S., President, in the Chair. 



William Henry Goss, Esq., Rode Heath, Cheshire, and Stoke- 

 upon-Trent, Staffordshire, was elected a Eellow of the Society. 



The following communications were read : — 



1. A letter from Dr. John Kirk, communicated to the Society by 

 the Right. Hon. Earl Granville, dated : — 



" H.M Agency and Consulate General, 

 Zanzibar, December 20, 1880. 



" My Lord, 



" It may be of interest to record the occurrence here of an 

 earthquake-shock felt in the island of Zanzibar at 6.58 a.m., mean 

 time, on the morning of the 18th inst. 



" Although the shock was very distinct, no damage appears to 

 have been done to any buildings in town. 



" It is now twenty-four years since a similar shock has been here 

 noticed ; but on the mainland, especially in the vicinity of Ujiji, 

 they are both more common and more severe than at the coast. 



" Shortly after the cable was laid between Mozambique and 



