388 > FISHES CHAP, 
mucus-connected, calcareous particles, as in Elasmobranchs, or as 
massive solid concretions in Teleosts, are present in relation with 
the sensory areas of the utriculus, sacculus, and lagena. 
In a few marine and in a large number of freshwater Teleosts 
Fic. 221.—Anuditory organs of Fishes. A, of a typical Fish; B, of Myzine,; C, of 
Chimaera ; and D, of Perca. a.c, Anterior canal ; ain’, am", am’, ampullae ; aim.n, 
nerves to ampullae ; ¢, semicircular canal (in Myzxine); d.e, ductus endo-lymphaticus ; 
h.c. horizontal canal; @, lagena; mc, macula acustica ; m.s, macula acustica of 
the sacculus; 7, nerves to ampullae; o, external aperture of the ductus endo- 
lymphaticus ; p.c, posterior canal; s, sacculus ; s.c, sinus endo-lymphaticus ; sf, 
superficial skin ; s.s, sinus superior ; wv, utriculus ; viii, auditory nerve. (From 
Wiedersheim, after Retzius.) 
the auditory organ enters into a more or less intimate connexion 
with the air-bladder by one of three different methods. The 
first and simplest is by the apposition of the extremities of a 
pair of caecal tubular prolongations from the air-bladder to the 
