CLASSIFICATION. History of /ehlhyology.— Among the ancient students of ichthyology, that branch of natural history which treats of fishes, the first to be mentioned, as usual, is Aristotle. In modern times ichthyology began to be culti vated about the middle of the sixteenth century by Behan, Rondelet, and Salviani. Their work was of value locally only. The first work of real value, and which marks the beginning of a sys tem based on scientific principles, was that of Willughby and Ray, which appeared in 1686 under the title Historia Piseium. Here a distinct effort at classification was made. They divided all fishes into two classes, Cartilaginei and Ossei. Each of these classes was divided into two groups, on the basis of the form of the body— the Cartilaginei into Longi, including the sharks, and Lati, including the skates; and the Ossei into Plani, including the flatfisho.s, and Nomplani, including all others. It is at once evident how artificial this classification is. Artedi, whose writings, on account of his death, were published by Linnnus, worked out a system of classification considerably influenced by Willughby and Ray. He included the cetaceans among the fishes. His system was adopted by Limnos in his earlier edi tions of Systema Nature, but later (1753) Lin naeus devised an original classification, which, among other changes, eliminated the Cetacea from the fishes and placed them with the mam mals. The elassification worked out by Bloch and Schneider was superficial in the extreme. The number of fins present was the basis of their division into Monopterygia, Dipterygia, etc. This work was published in 1301. Bloch, in 1732-95, published a large and important work on fishes, comprising nine volumes with fine illustrated plates, in which he described about four hundred species. Several other authors
wrote extensively on fishes during the last half of the eighteenth century and the beginning of the nineteenth. Among these is to be mentioned La c6pede, Histoire naturelle des poisso»s (5 vols., Paris, 1803), in which 1400 species were de scribed. During the first quarter of the nine teenth century Cuvier did much on the classifica tion of fishes, his system appearing in his Regne Animal (Bonn, 1330). The anatomist Johannes Midler published in 1846 a natural classification which influenced the systems to a very high de gree. He divided fishes into Leptocardii, Marsh pobranchii, Elasmobranchii, Ganoidea, Teleostei, and Dipnoi. Louis Agassiz (q.v.) advanced our knowledge both of living and fossil fishes. In fluenced by the latter, he divided the class into four groups on the character of their scales: plaeoid, ganoid, cycloid, and ctenoid. This classi fication. though convenient in many ways for the study of fossil remains, was adopted by scarcely any of the authorities. Albert Gfinther. in his Catalogue of Fishes in . . . the British Museum (London, 1859-70). has largely modeled the modern system of classification. Among the recent more influential American ichthyologists are Theodore Gill, the late E. D. Cope, and David Starr Jordan, whose historical review of ichthy ology in the Proceedings of the American Associa tion for the Advancement of Science for 1902 ie very complete.