300 Proceedings of Learned Societies. 



elevated semi-desert region, which is composed of a series of longi- 

 tudinal mountain ranges with alternating valleys and plains. The 

 most abundant rocks are those belonging to the Igneous and Meta- 

 morphic groups ; but Carboniferous limestone and Tertiary strata 

 are also found. 



The siliceous hot springs extend for some considerable distance 

 along a line of fissure in a granitic rock, parallel to the mountain 

 ranges. The water of these springs deposits silica in an amor- 

 phous and also in a granular form, sulphur also being deposited in 

 the interstices of the siliceous deposit. These phenomena are inte- 

 resting as illustrating the mode in which quartz veins are produced 

 in fissures in other rocks, from the older strata to the more recent 

 formations. 



Mr. Blake also described the mineral veins of the district there 

 occurring in porphyry. They yield metallic sulphurets, including those 

 of silver, lead, copper, and iron, with a little native silver and gold, 

 the veinstone being a friable quartz. The general direction of these 

 veins is north and south, and the amount of gold yielded by them 

 is more abundant near the surface than at greater depths. 



The Red Rock at Hunstanton. — Mr. Harry Seeley read a paper 

 on the geological characters of this rock, in which its physical struc- 

 ture was first considered, and it was shown to be divisible into 

 three beds, the uppermost of which is of a much Ughter colour than 

 the rest, the middle being concretionary in structure, and the lower 

 sandy. These beds, with the overlying white sponge-bed, were con- 

 sidered to belong to one formation, and were termed the Hunstanton 

 Rock ; but the thin band of red chalk some distance above was con- 

 sidered, though of similar colour, to be quite distinct,* as also was 

 the Carstone below. The author considered the lower part of the 

 Carstone to be of the age of the Shanklin Sands ; and as the Chalk 

 is not unconformable to the Hunstanton Rock, he concluded that 

 the latter could not be the Gault, but must be the Upper Greensand, 

 — a conclusion which he afterwards showed was supported by the 

 evidence of the fossils, and the occurrence of phosphate of lime. 



The seam of soapy clay which separates the Hunstanton Rock 

 from the chalk was supposed to have resulted from the disintegra- 

 tion of a portion of the former, the red colour of which the author 

 endeavoured to show was due to Glauconite. 



The upper part of the red rock of Speeton was thought to bo 

 possibly newer than that of Hunstanton, and perhaps to represent 

 the lime which cl:ipsc<l between the formation of the latter and that 

 of the bund of red chalk. 



LINNEAN SOCIETY.— March 27. 



On 'i hi: Phenomena of Variation as Illustrated by tite 

 Malayan PafilIOJTIDJ). — Mr. Wallace read a paper on this subject, 

 in wliidi be stated I hat flu- si u<ly of the PapinoxridsB of the Malayan 

 Archipelago was likely to illustrate the disputed subject of variation. 



* An analysis of this remarkable mineral will be found in the Intellectual 

 Obseeveb, vol. iii., p. 300. 



