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III. Cuntrihutions to the Anatomy of Fishes. — II. The Air-bladder and Weberian 
Ossicles in the Siluroid Fishes. 
By T. W. Beidge, M.A., Professor of Zoology in the Mason College, Birmingham, 
and A. C. Haddon, M.A., Professor of Zoology in the Royal College of 
Science, Dvblin. 
Communicated by Professor Alfeed Newton, F.R.S. 
Received June 9, — Read June 16, 1892. 
[Plates 11-19.] 
Contents. 
I. Introductory 
II. Historical 
III. Morphology 
IV. Morphological Summary 
V. Physiology . . . • 
VI. Concluding Remarks 
VII. List of Species described 
VIII. References 
IX. Description of Plates 
X. Reference Letters 
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I. Inteoductoey. 
Webee, in his classical memoir entitled “De aure et auditu Hominis et Animalium, 
Pars i., De aure Animalium aquatilium,” published in 1820, was the first to show 
that in certain families of Physostomous Teleostei, viz., the Siluridse and Cyprinidce, 
there exists a peculiar connection between the auditory organ and the air-bladder, by 
means of a chain of movably interconnected ossicles. To these two families, and to 
three others, viz., the Characinidse, Gymnotidae, and Gymnarchidae, in which this 
singular mechanism was subsequently discovered, Sagemehl (33) applied the collective 
name of Ostariophyseae (oarapLov, ossicle ; (fivay, air-bladder), for the reason that the 
possession of this highly specialized mechanism implied community of descent. Since 
the publication of Webee’s memoir, various contributions to this subject have been 
made, but deal for the most part either with special features, or with individual species, 
or with a very limited number of species in particular families. In no single family 
of Ostariophyseae has any attempt at present been made to institute a systematic 
S 
MDCCCXCIII. — B. K 20.5.93 
