32 



seous fishes is to be looked for in the number of the 

 branchiostegals of the gill-membrane, though regard 

 must also be paid to the general appearance, the posi- 

 tion and number of the fins, the place of the teeth, the 

 shape of the scales, and other external features, nor 

 should the importance in this regard of certain internal 

 anatomical characters be lost sight of, such as the stom- 

 ach, the caecal appendages of the pylorus, the intestines, 

 the bladder, etc. 



By following the rules laid down by Artedi and 

 their corollaries, the scientists who came after him were 

 able to differentiate the genera of fishes one from an- 

 other. In order, however, that the notion of genus 

 might have accorded to it the full value it deserved, it 

 was necessary, as Artedi clearly perceived, to establish 

 certain definite genus-designations. This was a com- 

 plete novelty, and one of the utmost significance. Pre- 

 vious to his time nothing of the sort had been con- 

 ceived, which is of course not to be wondered at, seeing 

 that the very notion of genus had not as yet become 

 an integral part of the zoologist's system of classification. 

 Up to that time it had been usual to identify any par- 

 ticular fish by citing a long list of synonyms, accom- 

 panied by a more or less lengthy series of descriptive 

 epithets. 1 Now, on the other hand, it is ordained that 

 to every genus a name shall be given consisting of one 

 word only, whereby all the species belonging under that 

 genus shall be known and distinguished. Furthermore, 

 the rules of nomenclature are also stated, in order that 

 the new system may be the more firmly established. 



There was every reason for Artedi to adopt radical 

 measures for imposing his reforms upon ichthyologists; 

 the names used at his day presented a picture of in- 

 credible confusion and muddle; for fishes belonging to 



1 As a typical example may be here cited the notation given 

 for cod by Willughby and Ray in the work quoted above: "Asel- 

 lus major vulgaris, Belgis Cabiliau, Mohrua vulgaris (maxima Asel- 

 lorum species) Bellon. Molva vel Morhua altera minori Rondel. Gesn. 

 p. 102 Aldrov. lib. 3 Cap. 6. A. Cod-fish, or Keeling". 



