29 
only be preserved in the gelatine medium, and slides thus prepared could 
not be used in the gas microscope on account of the heat. The gelatine 
medium was the best he was acquainted with for preserving the soft-bodied 
Infusoria. 
Mr. Leipner said it was impossible to predict which method of mount- 
ing would best suit any given species — and therefore it was well to prepare 
microscopic specimens in both ways. The Polysiphonia vestigiata, for 
example, could only be preserved in gelatine. 
Mr. C. O. Groome-Napier, F.G.S., exhibited several very beautiful 
photographs of gems, coloured with the transparent aniline colours, the 
effect of which was remarkably good, and decidedly superior to the best 
engravings of the same subjects, coloured by hand in the usual way. He 
explained the difficulty of getting good photographs of gems, owing to 
the * cross-lighting.' Mr. Napier also, in order to show the applicability 
of photography to the illustration of books, laid before the meeting a 
large number of small photographs of various natural history subjects, 
anthropological, entomological, geological, microscopic, zoological, &c, 
some of which were taken from the subjects themselves, others from pic- 
tures of them. 
MEETINGS OF SECTIONS. 
GEOLOGICAL SECTION. 
Thursday, February 28th— Mr. W. Sanders, F.R.S., F.G.S., 
President of " the Society and of the Section, in the chair. 
Mr. W. W. Stoddart, F.G.S., read the following paper upon the 
Geology of Dundry Hill : — 
The Jurassic series of rocks, of which the Dundry beds form a part, occupy a 
very large tract of English ground — they are found ranging from Dorsetshire 
through Somersetshire, Gloucestershire, Oxfordshire, Northamptonshire, and Rut- 
landshire, to Yorkshire. The Oolites always form very elevated hills, with fine 
bold escarpments, which tell plainly of the remains of gulfs, bays, straits, and 
other evidences of marine existence. Such views as these may be plentifully 
observed near Bath, Gloucester, Cheltenham, and Stroud, the highest being in 
Yorkshire. From this county the thickness of the rocks gradually declines to the 
West of England; Dundry Hill is about 700 feet above the sea level. The 
Jurassic rocks are thus divided, reckoning from the base, 
