242 



THE NATURALIST IN AUSTRALIA. 



order, the separate companies it may be in different directions, as though amenable 

 to strict military discipline. It commonly happens, moreover, that several larger 

 male individuals lead the van t *s \ /" j i 



m.'A 



of these moving battalions, and 

 seemingly fulfil the r6le of com- 

 manding officers. If followed 

 at a little distance, they will 

 continue their march at an 

 accelerated pace, but if over- 

 taken Or pressed hard, they ARMY CRABS , Myetent longicarpm. NATURAL SIZE. 



will disappear beneath the surface of the sand almost as suddenly as they emerged 

 above it. The body of these crabs being usually pale blue or lilac, and all the limbs 

 light flesh colour, they constitute, when seen in masses under their characteristic 

 auspices, a conspicuous feature in the landscape. 



The structural peculiarities of Mycteris distinguish it from all other crab 

 genera, and indicate and explain the singular celerity with which its members burrow 



into or underneath the sand, 

 together with their general 

 adaptation to their sandy 

 habitat. The body in these 

 crabs is almost globose, but 

 more dilated above. The 

 so-called foot -jaws or ex- 

 ternal maxillipedes differ 

 from the usual formula in 

 being set nearly vertical, 

 are much the wider supe- 

 riorly, and form in their 

 conjoined condition an in- 

 verted cone. When de- 

 scending into or burrowing 

 through the sand, the apex 

 of this cone is driven fore- 

 most; a spiral motion is 



W. Bmille-Ktxt, Photo. 



ARMY CHADS, Jfycterit platycheke. "A DESPERATE MELEE." Communicated to the body 



