NATURE NOTES. 121 
purple chert are found associated with it, and give it a 
very pretty appearance. Large specimens may be obtained 
here, and it is probably the best locality for it around 
Edinburgh, excepting the Garleton Hills. The rock in 
which it occurs has long lathe-shaped crystals of felspar set 
in a fine ground mass. Some of the vapour cavities contain 
very fair agates. ROBERT DYKES. 
THE coast section at the Heads of Ayr, Ayrshire, is for 
the most part composed of old red sandstone volcanic rocks, 
interstratified with ashy shales, limestones, sandstones, and 
conglomerates. Amongst these rocks are four distinct out- 
crops of amygdaloid, the homes of numerous agates and 
geodes, with their beautiful crystal contents. A month’s 
collecting there produced about fifteen hundred fairly good 
specimens of geodes and agates. Last summer, in a search 
of about two hours in the beach gravels, south of Dunure 
Point, four hundred and thirty-five specimens were obtained. 
ROBERT DYKES. 
OCCURRENCE OF GOETHITE ON BLACKFORD HILL. 
THE fibrous form of goethite occurs, though not very 
abundantly, on the south. side of Blackford Hill. It is 
associated with hematite, coating surfaces of the rock. 
J. B. Mears. 
DOUBLY-TERMINATED CRYSTALS OF QUARTZ ON CARNETHY. 
Prrrect doubly-terminated crystals of quartz occur in vapour 
cavities in the rock of Carnethy, Pentlands. They have 
VOL. I. fe) 
