172 \V. S. DEMBOWSKA. 



sponge several times and at last it always succeeds in assuming 

 the normal one in which the head touches the fore edge of the 

 case. The hooks of the 4th-5th pairs of legs, as usual, grasp the 

 inner surface of the sponge and the animal turns forward to its 

 ordinary position, pulling the sponge behind itself. 



In all described cases Dromia puts its own sponge on the back 

 in a correct position. But if the sponge belonged to another 

 individual, the position of it becomes often irregular, it may even 

 be put on with its concavity directed upwardly. Still after some 

 time the position will always be corrected. 



5. The behavior of the animal changes a little if the sponge is 

 lying with its concavity downward. In the majority of cases it 

 will be grasped with both chelae and, as before, the animal, 

 falling on its back, pulls the sponge over it. Now the crab 

 turns the sponge not only in a horizontal plane, but holding it 

 \vith ist-2d pairs of legs it turns its concavity downwardly. 

 After this the behavior becomes similar to the case i. 



6. Dromia may press the abdominal end of the body between 

 the sponge and the ground (the concavity of the sponge being 

 turned downward), then it enters under the sponge and grasps 

 its inner surface with the hooks of the 4th~5th legs. The sponge 

 becomes adjusted at once, or it may be turned correspondingly 

 in a horizontal plane. 



7. Before attempting to put the sponge on its back the animal 

 may turn its concavity upward and then it behaves as usual. 

 This turning occurs while Dromia pushes the edge of the case 

 with the forehead, or it presses the chelae between the edge of the 

 sponge and the bottom. If there are some small stones on the 

 ground the task becomes easier, as the stones prevent the gliding 

 of the sponge along the bottom, furnishing at the same time a 

 certain point of support for the animal. 



Dromia is able to surmount many unexpected difficulties when 

 putting the case on. If we put a few stones in the sponge, which 

 lies with its concavity directed upward, the sponge becomes too 

 heavy and the animal cannot turn it. After some time however 

 the sponge always will be liberated from the stones. In most 

 cases Dromia attempts at first one of the described above modes 

 of acting, as if there were no difficulty at all. But as those 



