PROC. BIOL. SOC. WASH. 95(2), 1982, pp. 408-411 LATERAL LINE OF DIPLOSPINUS MULTISTRIATUS (TELEOSTEL GEMPYLIDAE) Izumi Nakamura Abstract. — The existence of the lateral line in Diplospinus multistriatus has been questioned. The lateral line of D. multistriatus is described here and com-pared with that of closely related Paradiplospinus gracilis. Most of the (upper) lateral line of both species runs nearer the ventral contour of the body than the dorsal contour. This type of lateral-line conformation is found in some trichiurid genera, but not in other gempylid genera. Lateral-line scales of both species are tube-shaped with an irregular longitudinal slit. This type of lateral-line scale is not found in any other genera of Gempylidae or Trichiuridae. Since Diplospinus multistriatus was described by Maul (1948) from Madeira, considerable numbers of specimens have been collected widely in tropical and temperate waters of the Atlantic, Pacific and Indian oceans (Parin and Bekker 1972:161, Fig. 17). Maul (1948) studied the holotype with six paratypes and wrote, "the skin is smooth and there is no trace of a lateral line." Later, Tucker (1956) examined one of the paratypes and reported, "there are traces of an apparent and highly probable lateral line," but he did not mention this further. No other authors have paid special attention to the lateral line of D. multistriatus. While examining specimens of D. multistriatus at the National Museum of Natural History (USNM), Smithsonian Institution, traces of a lateral line were recognized. As there are no undamaged specimens of either D. multistriatus or Paradiplospinus gracilis, these observations are based on many specimens com-pounded to reconstruct the lateral line. Material examined. — Diplospinus multistriatus Maul: USNM 215428, 2 speci-mens (16.5, 55.2 mm SL), 21°30'N, 158°30'W, 19 Jan. 1970; USNM 215449, 6 (42.1-188.4), 2r30'N, 158°30'W, 23 Sep. 1970; USNM 100492, 1 (48.0), 29°00'N, 76°23'W, 28 Feb. 1914; USNM 226993, 3 (98.2-162.6), 27°45'N, 9ri8.5'W, 23 Feb. 1964; USNM 215397-8, 3 (134.7-203.0), 2r30'N, 158°30'W, 28 Feb. 1971; USNM 215395, 1 (141.0), 21°30'N, 158°30'W, 17 Sep. 1970; USNM 215433, 2 (142.5, 152.4), 21°30'N, 158°30'W, 16 Sep. 1970; USNM 194458, 1 (175.1), 29°40'N, 69°05'W, 29 Mar. 1957; USNM 219967, 2 (175.6, 213.3), 33°04'N, 39°29'W, 27 Apr. 1979; USNM 215391, 1 (188.4), 2r30'N, 158°30'W, 15 Sep. 1970; USNM 215394, 1 (203.8), 2r30'N, 158°30'W, 14 Dec. 1970; USNM 215454, 1 (232.8), 2r30'N, 158°30'W, 18 Sep. 1971. Paradiplospinus gracilis (Brauer): USNM 208104, 1 specimen (47.7 mm SL), 49°06'S, 120°15'W, 19 Dec. 1965; USNM 208446, 9 (141.0-335.0), 40°18'S, 39°04'W, 8 Mar. 1971; USNM 208448, 6 (161.7-320.0), 39°47'S, 43°38'W, 7 Mar. 1971; USNM 208449, 9 (182.0-349.0), 38°20'S, 54°33'W, 5 Mar. 1971; USNM 226992, 1 (355.0), 40°08'S, 82°47'W, 2 Oct. 1966. Identification Diplospinus multistriatus and Paradiplospinus gracilis are similar in external appearance. Specimens obtained by usual collecting methods are almost always
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