222 FISHES FOR THE MARINE AQUARIUM. 



the opossum shrimp it opens its mouth, and inflates 

 its cheeks so as to cause an in-rush of water, down 

 which the unfortunate crustacean is engulphed. The 

 opossum shrimp may be seen swarming in the water 



Fig. 152. 



Opossum Shrimp (Mysis chameleon). (Three times natural size.) 

 Fig. 153- 





Tail of Opossum Shrimp with otoconia. a. otoconia. 

 (Magnified ten times.) 



of most rock-pools. It is a queer little object, with 

 the very singular peculiarity of being able to hear by 

 its tail, at the base of which are certain cavities filled 

 with crystalline otoconia, or " ear-bones." 



