The importance of Marcus Elieser Bloch's famous book, published 1795, has not lost its value for modern ichthyology. While Linnaeus, 1758, listed approximately 400 species, Bloch's work contains descriptions and scientifically and aesthetically admirable illustrations of about 500 species. of these 267 were presented as new to science or needing new names. Many of his suggested names are still valid and in general use. Moreover, he introduced 19 new generic names, many of which were accepted. This splendidly and colourfully illustrated book - at last available on a CD-ROM - is a must for every scientist working in zoology, or just interested in the beautiful naturalistic drawings of Johan Maurits van Nassau and other specialists of that time.