26 ANIMAL PARASITES AND MESSMATES. 



Beroe, or a Pyrosoma, and from within this lodging they 

 give themselves up to the pleasm'es of fishing. 



The Phronima sedentaria which lodges with the salpa 

 seems to be scattered over the warm seas of both hemi- 

 si^heres. For the honour of the species, the females 

 alone seek the assistance of their neighbours, without at 

 the same time abandoning their characteristic robe. 

 The sexes differ little from each other except in size, 

 in the abdomen, and in the antennae. Maury has de- 

 scribed certain amphipod crustaceans which also inhabit 

 the Salpse. 



Another phronima described by Professor Claus, the 

 Phronima elongata, lives in the same manner ; but instead 

 of occupying a living house, it generally seeks an empty 

 lodging, in wliich it establishes itself like a pagurus. 



The ** Bernard the Hermit" of the Marseillaise fisher- 

 men, the Pyacles, becomes the messmate of an anemone 

 which Duges has called Actinia parasitica. According 

 to the observations of the learned professor at Montpelier, 

 the mouth of this anemone is always situated opposite to 

 that of the crustacean, to take advantage of the morsels 

 which escape from his pincers. Both of them profit 

 by this association ; and the opening of the shell is pro- 

 longed by a horny expansion furnished by th6 foot of the 

 actinia. 



On the const of England lives another soldier- crab 

 (Pagurus Prideauxii), which has as its principal messmate 

 a sea anemone called Adamsia, which Mons. Greeff found 

 at the island of Madeira. This pagurus is especially 

 remarkable for the good understanding which exists 

 between himself and his acolyte — he is a model Amphi- 

 tryon. Lieut. -Col. Stuart Wortley has watched it in its 



