動眼筋室 (Myodome) の變遷より見たる魚類,兩棲類,爬虫類,鳥類及び哺乳類の類縁及び分類に就いて。フナ,コヒ類(第1報)

Abstract

There are many kinds of forms in Carassius of Far East. From the standpoint of the evolution of the myodomes, two types can clearly be recognized. The one is the flat-type which the author calls “Hirabuna” and the other is the round-type. which is called “Maru-buna”. These two types can distinctly be separated by their morphology of the parasphenoids. The flat-type is more primitive than the round-type from the standpoint of the structure and development of the myodomes. If the parasphenoid of the flat-type is the same morphologically as that of Carassius carassius of Europe, the same scientific name should be given to the species of the flat-type. As the structure of the parasphenoid of the goldfish is about the same as that of the round-type, it is certain that the former has close relationship with the latter. Therefore, the species of the round-type should be called Carassius auralus which is the scientific name of the goldfish. In Ryukin it is found that each centrum of the vertebrae is only half as long as that of Carassius. Therefore, Ryukin has been stunted in development, resulting in a short form which should be named a dwarf. A species of Carassius from the river of Tam-sui in Formosa has also an abnormal backbone of which length is an intermediate between the backbone of Carassius and that of Ryukin. Therefore, it should be called a semi-dwarf.