PREFATORY NOTICE. 



The Proprietors of the Encyclopjedia Britannica having informed me of their inten- 

 tion to re-publish (in a separate form) the Systematic Treatise on the Class of Fishes, which, 

 under the term Ichthyology, I some time ago contributed to the Seventh (or current) 

 Edition of that work, I deem it advisable to prefix a Catalogue of the British Species 

 described and figured in Mr Yarrell's recent volumes. These had not approached comple- 

 ■ tion when the article above referred to was concluded ; and it will no doubt prove interest- 

 ing to the student of the general subject to be enabled to perceive the relations which our 

 indigenous species bear to the more gorgeous natives of foreign climes. By referring to the 

 Alphabetical Index which terminates the Treatise, the generic titles of the British Fishes 

 will be found in their systematic order, and the species named, many of which are of fami- 

 liar occurrence, will thus serve to exemplify the groups to which they respectively belong, 

 and so illustrate the Cuvierian arrangement of the Class. 



Of two hundred and twenty-six British species, described and figured by Mr Yarrell, we 

 believe that about one fourth part had not been previously included in any catalogue of 

 our indigenous productions ; and when we consider that above six thousand different kinds 

 of fishes have been already collected in the various waters of the earth (which, from their 

 prevailing continuity and comparative equality of temperature, afford an easy as well as an 

 ample field for migratory movement), we cannot doubt that the spirit of observation which 

 is now afloat will lead to the discovery from time to time of numerous other and most in- 

 teresting additions along our island shores. The admiration excited by the beautiful illus- 

 trations of the " History of British Fishes," and the facilities which they afford for the com- 

 parison and ascertainment of species, have indeed already conduced to that desired effect;' 

 and we believe that Mr Yarrell's manuscript notes will enable him to furnish a great in- 

 crease of ichthyological information to a second edition of his work, which we take it for 

 granted will be ere long called for. 



I shall here only further observe, that the vexata qucestio which regards the specific na- 

 ture and origin of the Parr, has been of late discussed with frequency and fulness by se- 

 veral ingenious, and one or two competent, observers. The most important point at issue, 

 viz. the identity of parr and salmon-smolts, has received some curious confirmation from the 



' See Transactions of the Royal Society of Edinburgh, vol. xiv. ; and Annals of Natural Hittory, No. iii. 



