102 Journal of the Asiatic Society of Bengal. [N.S., XIX, 
Fish, as we all know, are the most ancient vertebrates of 
which unmistakable remains have been preserved and even 
the most highly developed members of the class have retained 
many primitive characters, probably because they have never 
deserted their original medium. A few highly specialized 
species are able to breathe air for a time. a few can hop about 
and, a few can even glide through the air, but no species 
has become completely or even habitually terrestial or aerial, all 
are aquatic, having their habitation and reproducing their kind 
in water. The great majority, moreover, still retain what was 
probably their ancestral home in the sea. 
Professor Jordan in his “ Classification of Fishes” (1923) 
both the true fishes, the lampreys and the amphioxi, while in 
his “Genera of Fishes” (1917-1920) he gives the original 
the vast scope of his investigations and the great debt we owe 
him are clear without further comment, but the fact that he 
deals with fossil as well as recent genera should not be allowed 
to escape notice. 
subject index to all that has been written on fish and fisheries 
since the time of Linnaeus, with an author’s catalogue of pre- 
a “ 
