Lethrinus nematacanthns Bleeker, 1854a: 403, Nagasaki; Gunther, 1859: 456, Louisiades; Bleeker, 1876-77: 114, pl. 337, fig. 3, Amboina; Jordan & Thompson, 1912: 559, fig. 4, Tokyo, Wakayama (Japan); Herre & Montalban, 1927: 401, pl. 1, fig. 2, Philippines; Fowler, 1928: 215, compiled; 1933: 11, Philippines, Japan; Weber & Beaufort, 1936: 433, fig. 86, Indo-Australian Archipel; Okada & Matsubara, 1938: 217, Japan (key); Akazaki, 1962: 257, fig. 45, Mie, Wakayama, Amami Is. (Japan); Shinohara, 1963: 41, Ryukyus; Marshall, 1964: 198, Queensland (key); Kamohara & Yamakawa, 1968: 11, Amami; Sato, 1971: 129, fig. 2, Japan; Gushiken, 1972: 38, fig. 181, Okinawa Is.; Masuda et al., 1975: 59, fig. B, 233, southern Japan.
Lethrinella nematacantha; Munro, 1967: 326, pl. 43, New Guinea.
Lethrimus sp.; Tominaga, 1965: 186, fig. 139, Palau.

Specimens examined.

Syntypes. —RMNH5755 (2 of 3 individuals: 136 and 188mm standard length) from Nagasaki, Japan.
UMUTZ2311 (135), 2489 (137), 22171 (155), RMNH1047 (1 of 3 individuals: 75), 5755 (1 of 3 individuals: 77) from Nagasaki, Japan.
UMUTZ49153 (126) from Misaki, Japan.
UMUTZ52562 (52), 52561 (104) from Izu, Japan.
UMUTZ18609 (136) from Kochi, Japan.
UMUTZ50023 (116),50013 (130), 50012 (131), 50015 (144), 50014 (147), 50024 (155), 50040 (155), 49932 (185) from Goto Is., Japan.
UMUTZ52672 (70), 52671 (76) from Amakusa Is., Japan.
UMUTZ23926 (118) from Kagoshima, Japan.

D. X, 9; A. III, 8; P₁, 13; P₂. I, 5; C. 8 + 7; L. lat. 46 or 47; Ltr. 6 or 7/i/14 to 16.
Proportional measurements of some specimens are shown in Table 2.

Head length about equal to body depth. End of jaws on the vertical through anterior or posterior nostril. Side of maxillary ornamented with a row of tubercles, more con-spicuous in younger individuals. Posterior nostril closer to the anterior one than to eye.

Interorbital area flat or a little convex. Second dorsal spine longest and filiform. Usually 5 scale rows between lateral line and median dorsal spines. Inner base of pectoral densely covered with scales. Lateral teeth of jaws small and pointed.

Color. —Yellowish-gray, paler below. A black blotch slightly smaller than eye above the middle of pectoral usually seen. Several bright orange longitudinal stripes usually seen especially in younger individuals. Fins yellowish.

A relatively small species.

Distribution. —East Indies to central Japan and Australia.

Remarks. —This species can be easily identified by the characteristic long second dorsal spine and there has been no confusion on nomenclature.