82 MAEVELS OF THE ANIMAL WORLD 



or duckbill shares its underground quarters with 

 the Australian beaver-rat {Hydromys chrysogaster) ; 

 and the New Zealand tuatera lizard frequently 

 shelters various species of the petrel family within 

 its subterranean domicile, the feathered folk 

 generally taking up their residence at the right- 

 hand side of the dwelling, and the reptile on the 

 left. 



Even amongst fish we find that certain kinds 

 associate with other forms of aquatic creatures 

 and dwell together under the most extraordinary 

 circumstances. The small eel-like Fierasfer and 

 Encheliophis, found in the Atlantic, Indo-Pacific, 

 and Mediterranean Oceans, for instance, Uve in 

 the gullets of sea-cucumbers and star-fish, or within 

 the bodies of jelly-fish. They will also, at times, 

 ensconce themselves within the shells of pearl- 

 mussels, but not infrequently they suffer for their 

 temerity in having selected such a situation and lose 

 their lives by being encased in the pearly substance 

 which the bivalves are able to deposit upon any 

 matter which irritates their internal anatomy. 



Some fish will associate with anemones, and take 

 a toU of the food secured by their companions, 

 but as the hosts do not make any use of their 

 stinging powers in order to rid themselves of their 

 messmates, it must be assumed that they are quite 

 content to dwell in harmony with their self-invited 

 guests, and allow them to dine from their table. 

 Other fish are in the habit of dwelling within the 

 shelter of the stinging-arms of jeUy-fish, of which 

 one species affords its protection to the fry of horse- 



