Microscopical Society of Victoria. 
25 : 
the membrane a rich golden yellow. It is of great length 
in Patella tramoserica , the common species on all the 
coast of Australia, and lies in a peculiar coil or plexus, 
which will repay examination. All our species of Acmcea 
have a radula of similar structure, but the generic 
differences ought to be peculiar, as the branchial apparatus 
is entirely different. I have not been able to study them 
closely, but as far as I could observe, the teeth were more 
numerous and complicated, and the radula always shorter. 
In Trochocochlca, Diloma , Thalotia wo have short radulm, 
with a very complex dental system, mainly distinguished 
by the comb-like rows of uncini on the outer edge. In 
this they resemble all the Trochidw , but with modifications 
which will well repay study. I have tried to find if there 
were specific differences between Trochocochlca constricta 
and T. tamiata, two species which can only bo very 
doubtfully separated from one another. The results of all 
the examination I could afford to them did not clear up 
the question. In some specimens the differences were 
marked more than in others. In this case, and in all the 
family, I believe that the radula closes on itself into a tube, 
and that the two combs of uncini form the upper lining 
to the passage, forcing the food, which is vegetable, against 
the longer central cusps, and thus tearing it to the finest 
shreds. The common food of these is the Ulva latissima, 
so common on the rocks. The best animals for the study 
of these organs would be Chiton Australis and Haliotis 
nccvosa, both of which are of large size, so as to show the 
structure without much microscopic aid, and both of which 
are easily obtained alive. 
I cannot quite agree with European observers as to the 
structure of the radula, at least for our carnivorous 
mollusca. One of the most ravenous, as well as common 
forms upon our coasts is Buccinum alveolatum (Kiener). 
The radula is not easily extricated, but when taken from 
the end of the proboscis is not a bifid organ. It is a short 
spear with very prominent sharp cutting barbs at each side. 
I should say that its only purpose was to tear away the 
fragments of flesh from its prey. It is very easy to procure 
living specimens of this mollusc. A small limpet or chiton 
thrown into a rocky pool will very soon be covered with 
these little scavengers of the rocks. 
Our freshwater shells are mainly distinguished by the 
