背鰭4〜5軟条，51〜56軟条，臀鰭36〜42軟条，胸鰭17〜23軟条，腹鰭6軟条，鰓耙数4〜6+9〜14=14〜18，脊椎骨数26〜29+30〜33=57〜60。頭長は体長の22.2〜25.7％，肉質眼窩径は5.8〜7.0％，骨質眼窩径は11.4〜16.6％，吻長は7.5〜9.8％，両眼間隔は4.3〜6.0％，上顎長は9.5〜12.3％，尾柄高は2.6〜3.7％，胸鰭長は13.7〜22.5％，腹鰭長は11.7〜18.0（Arg.），17.2〜22.5％（Ch.），第1背鰭高は13.8〜25.8％，第2背鰭高は7.2〜10.0％，第1臀鰭高は2.8〜5.8％（Arg.），5.4〜7.9％（Ch.），第2臀鰭高は5.5〜7.8％。体は延長し，後半部は扁平して糸状に伸びる。頭はやや縦扁し，大きく，体長は頭長の4.5倍。吻は尖り，両顎をはるかに越えて前方に突出し口をおおい，後半分は隆起縁として眼下に達する。口は下位で，両顎は特に後方が突出可能。上顎後端は眼の後縁下に達する。上顎は下顎よりわずかに前方に突出する。絨毛状歯が上顎と鋤骨にある。短い髭が下顎先端にある。擬鰓はない。眼はむしろ大きく，頭長は眼径の3.5〜4.5倍。両眼間隔域は平坦で幅広く，ほぼ骨質眼窩径に等しい。両鼻孔は円形で眼の直前に位置し，後鼻孔の方が大きく，両鼻孔間に皮弁がある。腹鰭は喉位で，第2鰭条が最長で，その長さは体高にほぼ等しい。側線はやや不明確だが，前半はゆるやかに湾曲し，後半は直走する。小円鱗が頭部と体側に密に分布するが，脱落し易い。 　おそらく世界中の深海中層に分布するものと思われる。 　アルゼンチンでは記録されている（Menni, Ringuelet and Aramburu, 1984）が，チリでは記録されていない（Bahamonde and Pequeño, 1975）。2,700mの漁獲記録がある（Goode and Bean, 1895）。

（中村　泉）

　10 from Argentina (202.6-318.2 mm SL), 5 from Chile (190.1-323.4), FAKU 42738; AP 27-29, 31-33, 36-38; CP 96-99, 214. 　D 4-5, 51-56; A 36-42; P₁ 17-23; P₂ 6; GR 4-6+9-14=14-18; �X 26-29+30-33=57-60.
　HL 22.2-25.7 % of SL; FO 5.8-7.0; BD 11.4-16.6; SN 7.5-9.8; IO 4.3-6.0; UJ 9.5-12.3; CP 2.6-3.7; P₁L 13.7-22.5; P₂L 11.7-18.0 (Argentina), 17.2-22.5 (Chile); D₁H 13.8-25.8; D₂H 7.2-10.0; A₁H 2.8-5.8 (Argentina), 5.4-7.9 (Chile), A₂H 5.5-7.8.
　Body elongate with rather depressed head, compressed posteriorly, tapering to a slender tail. Head fairly large, about 4.5 times in SL. Snout pointed, projected beyond both jaws to form a rostral shelf over mouth, extending backward as a keel under eye. Mouth inferior, posterior parts of both jaws protractile. Posterior margin of upper jaw reaching to hind margin of eye. Upper jaw slightly more projected than lower jaw under rostral shelf. Teeth villiform in bands on both jaws and vomer. A short barbel on chin. Pseudobranchiae absent. Eye rather large, 3.5-4.5 times in head. Interorbital region flat and wide, its width almost as large as orbit diameter. Round nostrils situated just in front of eye, posterior one much larger, a flap between. Pectoral fin pointed, low and rather long, its length about 1.5 times in head. Pelvic fin thoracic, situated well forward of pectoral fin origin; second ray most elongate, as long as body depth. First dorsal fin with short base, first ray elongate and filamentous, about equal to head length. Second dorsal fin with long base, highest posteriorly, lowest at about two-thirds length from origin. Anal fin deeply notched at about two-thirds length from origin. Caudal fin weak, truncate. Anus situated just in front of anal fin origin. Small, deciduous, cycloid scales on head and body. Lateral line faint, gradually curved anteriorly and then straight posteriorly. 　Probably worldwide. 　This species is recorded in Argentine waters (Menni, Ringuelet and Aramburu, 1894) but not in Chilean waters (Bahamonde and Pequeño, 1975). It has been recorded from depths to about 2,700 m (Goode and Bean, 1895).

(Izumi NAKAMURA)

Distribution of Antimora rostrata in Patagonia.

Ventral view of head.

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