雙尾のハコフグ 岡田 要 社団法人日本動物学会 動物学雑誌 00445118 59 1 8 1950-01-15 A specimen of Ostracion farnasini having double caudal fins is dissected and obtained the following results. The extra-fin is found developing directly from the ventral side of the ventral basal plate of the tail, where the structur of the bone is quite malformed. In the median greater part the striation or the arrangemente of the constitution elements of the bone tends to the ventral as shown in Fig. 2b, instead of antero-posterior of the normal bone (Fig. 2a), and the fin rays develop so far as the extent of this deformed area. They count 10 in number plus a rudimental basal piece. The primary tail fin contains also 10 rays. This number of rays holds through to all normal specimen examined. Therefore, there is no reduction of number of rays both to the primary and the extra-fin. Moreover, 3 more bony pieces like basal piece of ray are found between the two tail fins. Further details can be studied on the accompanying figures, Fig. 1, general view of the fish, Fig. 2, inner structure of the tail fin, a) normal, b) doubled. 1950-01-15 110003360551 AN00166645 9997816 JPN NDL NII-ELS 1 A Coffer-fish with Double Caudal Fins Okada Yo K. The Zoological Society of Japan Doubutsugaku zasshi A specimen of Ostracion farnasini having double caudal fins is dissected and obtained the following results. The extra-fin is found developing directly from the ventral side of the ventral basal plate of the tail, where the structur of the bone is quite malformed. In the median greater part the striation or the arrangemente of the constitution elements of the bone tends to the ventral as shown in Fig. 2b, instead of antero-posterior of the normal bone (Fig. 2a), and the fin rays develop so far as the extent of this deformed area. They count 10 in number plus a rudimental basal piece. The primary tail fin contains also 10 rays. This number of rays holds through to all normal specimen examined. Therefore, there is no reduction of number of rays both to the primary and the extra-fin. Moreover, 3 more bony pieces like basal piece of ray are found between the two tail fins. Further details can be studied on the accompanying figures, Fig. 1, general view of the fish, Fig. 2, inner structure of the tail fin, a) normal, b) doubled. 岡田 要 Okada Yo K. 東大理動 Zool. Inst. Tokyo Univ.