TWO CITIZEN CRABS OF NONSUCH 



In the hand or under our lens this spells conspicu- 

 ousness and sets our placid theories at naught, until 

 examination of the first sargassum branch which 

 comes to hand reveals the irregular but very abun- 

 dant spots of the white, crystalline homes of bryozoa 

 or moss-animals which encrust the floats and fronds. 

 Our shell-hole mimics are outdoing themselves. I 

 collect a hundred crabs and find that about fifty are 

 pretending to be bryozoans as well as weed. This 

 resemblance tells us another fact — that moss ani- 

 mals inhabited sargassum weed ages before Planes 

 came on the scene. 



Just as a glistening mirror eclipses its frame, so 

 in the white-spotted crabs we forget not only the 

 mottlings of color and the pattern, but even the 

 outline of the crab fades from optical dominance 

 and we see only square, rounded, oval, rectangular, 

 double or dumb-bell-shaped white spots. Under 

 water another resemblance leaps to the eye — the 

 ever-ready banks of swimming feather-blades bear 

 a most perfect resemblance to occasional masses of 

 hydroids, those mothers and daughters of jellyfish, 

 whose slender little palm-tree oases sprout from the 

 edges of the fronds. 



Of the doings and adventures, dangers and joys 

 of the Wanderer Crabs in their home in open ocean 

 none may write. A biographical diary of Planes 

 would surely be an epic. In early July I found 

 numerous females with large masses of eggs held 

 safe beneath the abdomen, and when I came to 

 examine them closely there was the imprint of sar- 



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