30 ANIMAL PARASITES AND MESSMATES. 



eean, which clings to the sides of several kinds of Labra, 

 especially the smaller species. This crustacean is an 

 Anilocrian so common that we can scarcely imagine it to 

 have escaped the attention of any naturalist. Neverthe- 

 less, no work makes mention of the regular attendance 

 on the Labra by the Anilocra, which bears, we know not 

 why, the specific name of Mediterranean. Eondelet was 

 probably acquainted with it, when he spoke of the fish- 

 lice, which do not derive their birth from these fishes, 

 but from the sea mud. We often see males by the Bide 

 of females on the same individual. 



Some years ago a school of large cetaceans, known 

 under the name of Grindewhalls or Globicephak* were 

 pursued in the Mediterranean, and those which were 

 captured contained in the cavity of their nostrils, isopods 

 closely allied to the Cirolana spinipes, if not identical 

 with it. Till then the isopods had only been found on 

 sea fishes ; fresh-water fish are not, however, entirely 

 exempt ; in fact, a species of (Ega {(Ega interrupta of 

 Martens) has just been found on the skin of a fresh- 

 water fish of Borneo, the Notopterus hypselonotus. This 

 same genus includes a species {(Ega spongiophila) which 

 lives in the magnificent sponge, the Euplectella. We 

 know also a certain number of isopods which prefer the 

 interior of their neighbour's body, and instal themselves 

 in the cavity of the mouth, either to fish at the same 

 time as their host, or to seize the food on its passage ; 

 others are of such a cruel nature, that they make no 

 scruple to establish themselves in the stomach of a 

 peaceable white fish. Without injuring any important 

 organ, they penetrate in couples between the intestines, 

 and, concealed in this retreat, they seize by the narrow 



