37 
slightly overlapping the basal joints of all the limbs, and the anterior 
portion overlaps the base of the maxille. In the male the under 
surface is smooth and polished like porcelain, but in the female it is 
covered with a dense pile of short, stiff hairs. A character sketch 
of this species from my pen appeared in the ‘ Leisure Hour” for 
July, 1896. 
Neither of the two species of “yas from these waters has yet come 
into my possession, and of the next genus I have obtained but one of 
the two—/%sa tribulus, which I exhibit. It had, unfortunately, met 
with an accident before it was caught, by which its rostrum was 
injured. The fisherman to whose sympathy with my weakness for 
what his tribe are pleased to call “‘curios” I am indebted for this 
specimen, was somewhat startled to see a mass of red sponge walking 
along where it had fallen from the crab-pot, and it was handed to me 
as a curious sponge, to see if I was sharp enough to detect its real 
nature. I “spirited” it at once, just as 1t was, without detaching the 
sponge, which, however, I have since touched up with colour to 
make up for that which the spirit dissolved out. Observe that all its 
limbs are short—that is, for a spider-crab. It keeps them well 
hidden away under its load of sponge (which has shrunk from its 
original dimensions), but it disguises them by attaching bits of weed, 
etc. Note how its esthetic sense has been gratified by placing small 
pieces of the white calcareous sponge, Lewcogypsta, on each leg. Is 
this to create the optical illusion of detaching the legs from the body ? 
We know how important a part white spots play in protective colour- 
ing, and it looks much as though the crab had a similar purpose in 
view here. 
Pressure of other engagements prevents me from proceeding 
further with this subject just now, but I trust you will forgive the 
brevity of this paper, and regard it merely as an introduction to the 
specimens exhibited. Few field naturalists appear to be working at 
our indigenous Crustacea, though I fancy there is a good deal yet to 
be learned concerning them. .I hope before long to trouble you 
again with some brief notes on other of the crabs of Gerrans Bay. 
