236 HALF AN HOUR WITH CRUSTACEA. 



which grow on and nearly cover its carapace. The 

 seaweeds are generally red ones, and so the crab is 

 well concealed by them. It was formerly thought 

 that the animal dressed itself up in this fantastic 

 garb, but it is now known that they grow naturally 

 upon it. All the slow-moving crabs are liable to 

 similar parasitic growths, and the so-called " Spider- 

 Fig. 127. 



The Spider-crab (Ilyas araneus). 



crabs " especially. One of the latter, known as the 

 " Long-legged Spider-crab " (Stenorynehus phalan- 

 gium\ has a small, triangular carapace, not unlike a 

 pair of kitchen bellows. Its legs a^fe long, hairy, 

 and quite spider-like. This is one of the most 

 abundant of our triangular crabs, and is known from 

 its frequenting the mouths of rivers. It seems to 

 prefer tolerably deep water, but it is to be found 



