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Yorkshire. It differs from its near ally, H. pulchellum 
(Dicks), in its leaves being broader and larger, and in the 
male flowers being separate and distinct. Besides, H. niti- 
dulum affects rotten wood, decayed bark, or decomposed 
vegetable matters as a site for its growth; whilst H. pulchel- 
lum always grows in the fissures of rocks. 
Mr. Plant exhibited a rare hydrocarbon mineral from peat 
found near Manchester, The mineral crystals which encrust 
and radiate over the inner surface of the pine bark in the 
specimen exhibited, belong to the Fichtelite group of the 
hydrocarbons, and may be subsequently determinable to 
this. If so, it will be the first instance of Fichtelite having 
been recorded as occurring in Great Britain. 
Mr. Plant then read a paper on the gradual decrease of 
wild birds during the last 25 years west of Manchester. 
The list included all the birds — residents, visitants, and 
casual stragglers — observed in and near to Peel Park, in the 
years 1850-60-70, and the numbers resident in 1871-75. 
The birds recorded in 1850 were 71 ; 1860, 42; 1870, 19; 
and in the last five years only 8 resident birds were to be 
found. 
The causes for the decrease were chiefly increase of 
building, destruction of trees from many causes, and general 
absence of food and shelter for birds. 
