REPORTS FROM THE SECTIONS. 278 
inch, being finer than English specimens, which average 48,000 
Two or three species of Stauroneis were also found, on one of 
power of my +s-in. immersion of large angle. I have no doubt 
that the lines existed, though I could not see them, as 
some of these Witzschia are among the most difficult of our 
a) yt; diagonal 
e 
but about 65,000 to the inch, and a good test for a large-angle 
4-Ine w valves were also found of a curious 
oO 
Pleurosigma, very broad with obtuse ends, and totally devoid of | 
_ markings whatever, as far as I could ascertain with any power 
to the 5-in. The species most plentiful in these Darling Harbour 
being the smallest variety known, as Prichard mentions some as 
small as 1,600”. Beaks range other parts of Darling Harbour will 
urnish numer ther species of diatoms, but I can Dau 
mention this mal of one gathering 
d near the mouth ye Cook’ s River will, if collected 
e mu 
from suitable spots, fag ich return. From a sample sup- 
plied me by Dr. Tucker I oe several ation on which are the 
7 ) 
inch. Pritchard a for English specimens 36,000 ; agen aae 
ns 
recommend this locality to any one collecting diatoms, as 
certain that os — be found a si — of wie 
forms both of known and unknown specie 
It appears re e however that it is in fresh water that 
the greatest variety of o r local pain nenagee are to found. 
My first trial for fresh peice specimens was in the sediment 
obtained from the top of a filter sapeliod pace water from the city 
yielded alarge supply of diatoms, spicule, 
