SCIENTIFIC MEMOIRS. 
VOL. IV.—PART XVI. 
Articute XVIII. 
On the Structure and Characters of the Ganoidei, and on the 
natural Classification of Fish. By J. MtuuerR, Professor of 
Anatomy in the University of Berlin*. 
[Read before the Academy of Sciences at Berlin, Dec. 12, 1844.] 
NO branch of natural history presents a more striking proof 
of the importance of a knowledge of extinct fossil genera in the 
natural classification of animals generally, and in particular of 
living species, than ichthyology. Paleontology has essentially 
altered the basis of this part of the system. The great differ- 
ence existing between the fossil remains of fish has required the 
formation of whole orders and families, which have few or no 
representatives in the present world; and the isolated forms 
which have lasted until our own times must vacate the position 
systematically assigned to them, to be included among the pre- 
vailing groups of a former world in perfectly distinct places, 
and in other orders. The propriety of these arrangements 
principally depends upon the correctness of the supposition, 
that the fundamental differences existing in the remains of 
skeleton and cuticular appendages which have come down to 
_ us, were connected with equally important and decided differ- 
ences in the general organization. How far such connexion 
extends, however, can only be ascertained from an examination 
of the existing creation. Although the systematic results of 
the examination of fossil fish have become so extensive and 
important, nevertheless it is undeniable, that the anatomy of 
living fish has not been sufficiently determined and studied to 
* Translated from the German by J. W. Griffith, M.D. 
_ VOL. IV. PART XVI, 20 
