20 THE NATUEAL HISTOET EETIEW. 



and the descriptions of the new species being scattered throngli a 

 great many Journals, Voyages and Eeports, such a general synopsis 

 as the present in which all the species of which descriptions are 

 accessible are contained, will meet a real want in Ichthyology. 



Dr. Giinther has commenced his labours, as we have already said, 

 with the Teleostian Fishes of the great order " Acanthopterygii," 

 as defined by Johannes Miiller in his celebraCted modification of 

 Cuvier's System. Frequent, he says, as have been the objections 

 against these modifications, " no one has yet proposed any arrange- 

 " ment which would give a more satisfactory result if put to the test 

 " of carrying it out to a detailed subdivision." Under these circum- 

 stances our author, who was, we believe, in former years a pupil of 

 the great anatomist, has been satisfied to adopt, nearly without 

 alteration, his master's views as a basis, and to distribute the species 

 into natural minor divisions according to Miiller's ordinal arrange- 

 ment. As regards the points mostly to be attended to in subdividing 

 the orders, Dr. Giinther is of opinion that there is no character 

 equal in importance to the structure and position of the fins, as these 

 organs stand in immediate connection with the entire habit of fishes 

 and their mode of life, and therefore supply the best indication of 

 their natural affinities, although isolated exceptions are occasionally 

 met with. Another character of great importance for the distinction 

 of the families is, according to Dr. Giinther, the number of the 

 vertebrae, but whether this has any bearing of still greater import 

 cannot exactly be determined at present, as the osteological portion 

 of the collection has not been yet completely examined. 



The first three volumes of Dr. Giinther's work are entirely taken 

 up with the order " Acanthopterygii," of which no less than 3481 

 species are given, and 2811 of these are considered to be well 

 characterized. In Cuvier and Valenciennes, Histoire Naturelle des 

 Poissons (1828-1849) — the last published general work upon this 

 class of Vertebrates — only 2146 species of the same group are 

 enumerated, and upwards of 600 of these are considered by Dr. 

 Giinther to have been merely nominal species, so that we see at a 

 glance what large additions have lately been made to our knowledge 

 of this class. 



In a synopsis of the Acanthopterygian Eishes at the end of the 

 third volume, Dr. Giinther furnishes the following scheme for the 

 primary division of this Order : — 



