29-2 PISCES. 



but of one family ; and which, with the jaws perfect, have the filaments of the gills 

 arranged in tufts upon the arches. 



In the rest, which include by much the greater number of the True Fishes, the cha- 

 racter employed bv Rav and Artedi, and taken from the nature of the first rays of the 

 dorsal and anal fins, furnishes two principal divisions. These are Malacofterygii 

 (soft fins), in which all the rays, with the occasional exception of the first dorsal or the 

 pectorals, are soft or jointed ; and Acaxthopterygii (spiny fins), in which tbe first 

 portion of the dorsal, or first dorsal when there are two, always have spinous rays, and 

 which have also some in the anal, and at least one in each ventral. 



The first of these sub-classes may be divided according to the position of the ventral 

 fins. If these are on the belly, the fishes are Abdominal ■. if attached to the shoulder, 

 they are Sub-brachian ; and if wanting, they are Apodal. Each of these orders com- 

 prises certain families, of which the abdominal ones are very numerous. 



• The Spinous Fishes do not admit of this kind of division ; but must be separated into 

 families, the characters of which are, in many instances, well defined. The same gra- 

 dation of families cannot be traced among Fishes as among Mammalia. Thus, the organs 

 of sense, and those of generation in some, indicate connexion between Cartilaginous 

 Fishes and Serpents, while the imperfect skeleton of others of these fishes indicates a 

 relation to Mollusca and Worms, [though the far more important disposition of the 

 nervous system, characteristic of the type of Vertebrated Animals, is still retained. 



The abstract of Cuvier's arrangement of Fishes, by far the best — that is, the most 

 natural, which has hitherto been made, or which there are materials for making — may 

 be given briefly thus : — The series of True or Bony Fishes he divides into the two divi- 

 sions already mentioned, as distinguished by the rays of the fins. The Spinous Fishes 

 form a single order, and this order he divides into fifteen families, which he names, 

 from some well-known species as the type, or for some marked peculiarity of character 

 which belongs to the whole of the family and to no other fish. The Soft- finned Fishes 

 he divides into three orders, according as the ventral fins are abdominal, thoracic, or 

 wanting ; and the Cartilaginous Fishes he divides into two orders, — those with free 

 gills, and those with the gills fixed.] 



THE FIRST ORDER OF BONY FISHES. 



ACANTHOPTERYGII. 



This first order contains by far the greater number of the Ordinary Fishes. Their characters 

 are spinous rays in the first dorsal, if there are more than one, and spinous ravs in the first 

 part if there is one only; but sometimes, instead of a first dorsal, thev have free spines 

 without any connecting membranes. The anal fin has also its first ravs spinous ; and 

 there is generally one such ray in each ventral. [When we speak of the first rav of a fin, 

 we mean the one nearest the head of the fish, which is easily understood in the other fins, and 

 is the extreme one either above or below in the caudal.] 



The spinous fishes are arranged into fifteen families, and some of these families contain a 

 vast number of genera. The families are named, as already noticed, from some well-known 

 species, or some strikingly peculiar character. [When a species is the tvpe, the technical 

 name of the family ends in id<z or oida, the Greek word for resemblance ; and when it is 

 founded on a peculiar character, the name is descriptive of that" . 



