THE AUSTRALIAN NATURALIST. 151 
ON RICCIA FLUITANS. 
By H. E. Fincxkn. 
At the February meeting I exhibited a fine bunch of this rare 
and beautiful plant, which I was fortunate enough to have raised 
from some stray fragments which were floating in a fish bowl in 
which I had landed aquarium fish from the United States of 
America. 
This floating plant in colour as well is in shape, is a fine ad- 
dition to a fishtank, so different from anything else amongst the 
floating plants, besides it is most helpful in the rearing of young 
fish. Its ball-like mass of separate plants affords an ideal hiding 
place for the young fish; in this they seek protection from their 
enemies, which very frequently are their own parents. 
IT am endeavouring to raise the terrestrial form, which should 
prove an interesting exhibit. 
I am indebted to our President for the following information 
regarding the plant: The genus Riccia is made up of small 
plants, which nearly always form more or less complete rosettes 
on soil. Some species are monoecius, others dioecius. RF. flui- 
tans has the former habit. It grows in thin sterile patches, float- 
ing in stagnant water, or frequently in fertile layers on mud, 
green or yellow-green. It is recorded from Black Spur and 
near Marysville, Gippsland, Victoria. 
; 
OBSERVATIONS ON LARVAE OF DANAIS MENIPPR. 
By Miss M. McANENE. 
We had three Danais larvae under observation for three weeks. 
On the 23rd April two caterpillars attached themselves to the 
top of the box within about half an inch of each other. As 
they always hang head downwards, completing the cremaster 
necessitated a fair amount of turning or twisting. Occasionally 
in the wriggling, one would appear to move in too close proxim- 
ity to the other. The disturbed one immediately jerked its body 
in quite a fierce-looking manner towards the offender. This con- 
tinued for more than three hours. We wondered if the seeming 
ferocity was a form of protective mimicry. Next morning the 
chrysalids were quite complete, facing in opposite directions— 
one towards the light, and the other towards the back of the box. 
On 27th April the third caterpillar moulted. and attached 
itself to the top of the box, about an inch from the other two— 
the last larval skin falling to the bottom of the box within 12 
minutes of the commencing of the cremaster. 
