2657 
THE GEELONG NATURALIST. xX 
LAMELLIBRANCHIATA. 
Unio australis, (Lamarck), Philippi. In most, if not all, of the 
rivers throughout Victoria. 
Unio depressus, Lamarck. Barwon R. (Mulder); Yarra R. 
(Heidelberg); Nepean R., N.S.W. (type). 
Corbicula Angasi, Prime. Moorabool R.; Warrnambool, &c. 
Corbicula Deshayesi, Smith. Colac. 
Sphaerium Macgillivrayi? Smith. Water holes, Cape Otway 
Ranges and L. Connewarre (Mulder). Valley Lake, Mount 
Gambier. 
Pisidium Etheridgei, Smith. L. Connewarre (Mulder); Carrum 
Swamp; Yan Yean Reservoir (fype). 
OUR PEAT DEPOSITS. 
By W. Eruey. 
Read before the Geelong Field Naturalist Club. 
Iw taking up a subject of this nature, it will be necessary in the 
first place, to take a general view of the origin of these deposits. 
We may then notice other formations, allied to peat by their 
structure, and point out their differences. From these consider- 
ations we purpose to review somewhat in detail our local examples 
of modern vegetable deposits. ; 
The most superficial observer (of course, no intention of giving 
offence is meant by hinting that a field naturalist can be superficial) 
may see the fibrous nature of the peat. 
How is this fibrous woody nature preserved? In the ordinary 
course of vegetable decomposition, the component elements are ex- 
posed to the atmosphere, and in the course of ages fertile 
moulds, usually black in colour, are produced, such as the black 
soil of Russia, the surface of the American prairies, &c. But their 
primal form has almost whoily disappeared. 
Not so with peat. Growing on a soft spongy mass it thrives, 
and decays and is pressed down by succeeding vegetation, until 
removed entirely from atmospheric influence. The decompo- 
sition ceases, and we find the woody nature retained with sufficient 
carbon left to make a very comfortable fire for the peasant of 
Treland or Germany. 
There are however limits to the formation of this substance— 
it is confined entirely to the temperate and cold regions of the globe, 
the extreme heat of the Torrid zone, necessitating a decomposition 
so rapid, that peat is not produced there except in mountainous 
regions. i TT : 
As bogs have the property of preserving objects which happen 
to become submerged in them, many discoveries of fossil animals 
and trees have been made in them in the Old World. 
