AUSTRALIAN MALACOSTRACOUS CRUSTACEA. 203 
3. Pseudocarcinus gigas (M.-Edw.). “The Giant Crab.”-— 
As its specific name implies, this is a giant amongst crustaceans, 
the carapace sometimes reaching a breadth of two feet. On 
account of the enormous size of the chele, it can give a tre- 
mendous crush—we cannot call it a “‘nip’’—with those weapons. 
Its habitat is Bass’s Strait, between Tasmania and Victoria, 
where it lives amongst stones, for which it is well adapted, as, if 
it kept perfectly still, there would be some difficulty in discrimi- 
nating between the stones and the Crab. The colour varies from 
red to yellow, with black fingers. 
4. Pilumnus jfissifrons (Stimps.).—This small species frequents 
stones, &c. (just below low-tide mark), which are covered with 
mud and alge, and is common around the shores of Port Jackson. 
The carapace being very setose, catches and holds sediment, thus 
giving the Crab the appearance of a small round protuberance on 
the stone which it frequents. 
5. Pilumnopeus serratifrons (Kin.).—Common on rocky shores 
of Port Jackson and other inlets along the coast of New South 
Wales, especially in those parts that are covered with small 
stones, under which they seek concealment. They are subject 
to a good deal of variation in colour. Length of carapace, 2 in.; 
breadth, lin. Found along the east coast of Australia, and in 
New Zealand. 
6. Leptodius exaratus (M.-EKdw.).—May be procured in similar 
situations to the preceding, but is not very common. The cara- 
pace is very flat, and the last pair of ambulatory legs is twisted 
upwards to enable it to grasp the under surface of stones, under 
which it has sought refuge. In coloration it varies according to 
situation, some being white, others mottled, and others quite black. 
7. Neptunus pelagicus (M.-Kidw.).— A species which is very 
widely diffused, undergoes a good deal of variation, and is very 
abundant. It is the common Edible Crab of the Sydney fish- 
market. One peculiarity which I have noticed is that the sexes 
for the most part of the year live strictly apart. I have seen at 
one time scores of females with not one male among them, and 
vice versd. To be quite sure, I enquired of the fishermen whether 
they put them in separate heaps, but they assured me that they 
did not. This form is very nearly allied to the Lupa bellicosa of 
America. 
