MARINE MISCELLANEA. 241 



instance, living in its vicinity, had the large, but somewhat shorter and thicker, 

 fighting chrela 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 chsela orange red. This species 

 is possibly identical with Gelasimus mriatus. 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 chsela 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. platyclieles, 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, M. 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 Eoebuck 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 



