MARINE MISCELLANEA. 241 
instance, living in its vicinity, had the large, but somewhat shorter and _ thicker, 
fighting chela in the male cream colour, while the body and all the other limbs 
were a slaty black. The smallest species of all, having a carapace, or shell, scarcely 
half an inch in diameter, makes its burrows in sandy situations, far up on the 
beach near high spring level. Its strikingly delicate colouring included a pale lilac 
carapace, rose pink legs, and a large lemon-yellow fighting claw. Out on the 
mud-flats below the mangrove zone there was a species nearly as large as the scarlet 
one, but much less abundant, having a purple carapace, lilac and ochre yellow ambu- 
latory limbs, and a portion only of the large fighting chela orange red. This species 
is possibly identical with Gelasimus variatus. The fifth variety observed at Broome 
was smaller than the preceding one, had the carapace in the male bright blue cen- 
trally, with a brown anterior border. The ambulatory limbs were pale yellow, and 
the fighting and rudimentary chela a most delicate rose pink. It was most abundant 
in a zone between that of the scarlet type and the form last referred to. Probably 
one or more of these Broome Gelasimi will be found on nearer investigation to be 
new to science. 
An essentially characteristic Australian group of the Crustacean class is that 
represented by the genus Mycteris, and including what are familiarly known on 
the Australian littoral as “ Army Crabs.” Two species have been described, Mycteris 
longicarpus and M. platycheles, which differ from one another chiefly in the relative 
length of their limbs. Tasmania in the South, and Port Jackson and Botany Bay, 
New South Wales, on the Eastern Australian sea-board, represent their range 
of distribution, as recorded in Mr. Haswell’s Monograph. The larger crab, MJ. longi- 
carpus, has, however, been observed by the writer in abundance in Moreton and 
Wide Bays, on the Queensland coast, and the second or an_ allied form at 
Carnarvon and as far north as Roebuck Bay, in Western Australia. Both species 
agree with one another in the remarkable habits which have gained for them 
their above named popular title. Sandy-flats, in more or less sheltered bays that 
are extensively exposed at low-water, represent the conditions under which 
they are most abundantly met with. They are eminently gregarious, and in the 
situations indicated associate together in numbers that may often be more correctly 
expressed in terms of thousands rather than of hundreds. When the tide is high 
nothing is seen of them, nor, probably, are they visible till some time after the 
tide is down. Then, as though by magic, armies of them will rise up from 
beneath the previously barren sand, and, assembling in battalions, march in open 
HH 
