648 Geological Society : — 



and a few fossils. At the foot of the hill, a large brickfield shows 

 the following sequence : — 



Feet 

 8. Grey, creamy- weathering clay (zone of Exogyra virgula) ... 4 

 7. Grey, creamy-weathering clays with crushed shells, darker 



and slightly selenitic towards the base about 17 -j 



6, 5, & 4. Two bands of creamy limestone, with marly clay 



between (Pictonia cf. Cymodoce, Pholadomya cequalis) 4 



3. Dark grey, brown-weathering clay, with occasional phosphatic 



nodules 8 



2. Black shaly clay, weathering lilac-grey with yellow stains, 



highly selenitic (Bclemnites abbreviatus, B. nitidus, Ostrea 



deltoidea, Gryphasa dilatata, Trigonia Voltzti, etc.) 14 



1. Band of grey limestone (Perisphinctes decipiens, Trigonia 



Juddiana) at the base. 



There have also been dug up, probably from the selenitic clay 

 (No. 2), doggers composed largely of Serjmla tetragona, Sow., and 

 Arctica (Cyprina) cgreniformis(?J, Blake, yielding many other fossils, 

 including Cardioceras alternans (von Buch) and Belemnites nitidus, 

 Dollf. The possibility of the selenitic clay being Ampthill Clay is- 

 discussed, the conclusion being that only Lower Kimeridge Clay is 

 exposed in this section. 



(2) The rock of Studley and Arngrove, described by Phillips as- 

 an argillaceous chert, is shown to be mainly composed of the globate 

 spicules of the tetractinellid sponge Rhaxdla. It has a much more 

 limited extension eastward than the geological map would suggest - r 

 but, on the other hand, it is found to form part of the outcrop of 

 normal Corallian rocks from Waterperry by Stanton St. John to 

 Holton Wood. Its exact relation to the Oxford Clay is described,, 

 and an increased list of fossils is recorded from it. 



Palseontological notes are given on certain species of Lamelli- 

 branchia and Annelida, chiefly from the Lower Kimeridge Clay. 



2. ' On the Skull and greater portion of the Skeleton of Gonio- 

 pJwlis crassidens from the Wealden Shales of Atherneld (Isle of 

 Wight).' By Eeginald Walter Hooley, F.G.S. 



December 5th. — Sir Archibald Geikie, D.C.L., Sc.D., Sec.R.S., 

 President, in the Chair. 



The following communications were read : — 



1. 4 On the Geological Conditions which have contributed to the- 

 Success of the Artesian Boring for Water at Lincoln/ Bv Prof. 

 Edward Hull, M.A., LL.D., P.K.S., F.G.S. 



This boring has its source of supply in strata which rise to the 

 west, but to the east dip down towards the JSTorth Sea. There 

 exists no information as to whether the eastern border of the 

 water-bearing formation thins out against a concealed ridge of 

 Palseozoic rocks. The water-yielding stratum is reddish, soft, 

 porous, sand-rock, reached at a depth of 1561 feet and penetrated 

 to a depth of 474 feet. About one million gallons of water rise 

 to the surface daily. The sand-rock belongs to the New Red; 

 Sandstone, which crops out from York to Nottingham with a breadth 

 of about 8 miles. The hydraulic pressure at the bottom of the 



