ARCHITECTUEAl EFFOET 9] 



Aa earlier observer, Bosc, wto studied this same 

 species in Carolina, declares that these crabs were to be 

 seen in thousands and even in millions on the margin of 

 the sea or of tidal rivers. He remarks that, if a man or 

 any animal comes among them, they lift up the large claw, 

 and holding it forward, as if challenging theii opponent to 

 fight, in that attitude they scurry oS sideways. They 

 bave, he says, a great number of enemies among the otters, 

 bears, birds, turtles, alligators, and the like, but they are 

 so prolific that the devastation made among them by these 

 foss is imperceptible. He occasionally saw the ' calling 

 crabs ' swarming over a carcase on the shore and disputing 

 with the vultures for strips of the carrion. He was very 

 anxious to see them make their burrows, but they never 

 would work in his presence, doubtless not from shyness, 

 but from some prudential motive. Gelrisimus minax, 

 Leconte, the largest of the American ' fiddler-crabs,' lives 

 in salt marshes or fresh water. Over the mouth of its 

 burrow Mr. T. M. Prudden ascertained that this crab often 

 constructs a regular ovenlike arch of mud, and that it sits 

 in this doorway on the look out for whatever may befall. 

 Professor Smith kept a large male of this species in a 

 glass jar containing nothing but a little siliceous sand, 

 moistened with pure fresh water, for over six months. It was 

 for ever pacing round the jar and trying to climb out, was 

 never observed to rest or show fatigue, ' and after months 

 of confinement and starvation was just as pugnacious as 

 ever.' 



The species Gelasimus arcuatus, de Haan, already 

 mentioned, was observed by Krauss in South Africa as 

 occupying muddy ground, and having a bluish-grey colour 

 suitable to its residence. The appropriateness of the 

 generic name will be appreciated in the light of his in- 

 cidental remark that ' it is truly comical to see these crabs 

 with uplifted arms in countless numbers scampering over 

 the dark mud.' 



Gonoplax (originally spelt Goneplat and Gonejdax), 

 Leach, 1814, is a North- Atlantic and European genus, 

 which till lately contained only one species, Gonoplax 



