108 NORTHERN ZOOLOGY. 



The preceding family is the last of that division of the Osseous Fishes which 

 is named Acanihopterygian, or Spiny-finned, on account of the spinous rays 

 which support the whole of the first dorsal, when there are two of these fins, or the 

 forepart of the fin when there is only one : in some instances all the rays of a soli- 

 tary dorsal are spinous, and occasionally the spines are free or unconnected by 

 membrane. The anal has also one or more spinous rays, and there is generally 

 one in each ventral. Several genera, however, are admitted into the division, 

 although the spinous character of their fins is very imperfect, and also some which 

 are absolutely destitute of spines*, because their habits and their anatomical struc- 

 ture, in general, ally them intimately with groups that are decidedly acanthoptery- 

 gian. 



The exposition of Cuvier's system of arrangement occupies more space in 

 the preceding pages, than may appear to be necessary in a local Fauna ; but we 

 found it difficult to give, in any other way, correct characters of the various groups 

 of spiny-finned fish which fall within the proper scope of the work, or to exhibit 

 their true situation in the system, without a reference to the intermediate or con- 

 necting families. For it happens that this great division, though richer in genera 

 and species than any other, does not admit of being split into orders, its only 

 practicable subdivision being into natural families, which are so intimately linked 

 to each other, that, as Cuvier says, the whole division might be considered as one 

 great family. Owing to this close dependence of one group of acanthopterygii 

 upon another, they are often more readily distinguishable by comparative cha- 

 racters than by positive ones, thus requiring the whole series to be noticed. These 

 remarks are not so applicable to the remaining divisions of the class, and we shall, 

 therefore, in treating of them, greatly restrict our quotations from Cuvier. 





* Zoarces and maltke for instance. 



