(Günth., Proc. Zool. Soc., 1862, June 24.)
6. Ophiocephalus siamensis.
D. 42. A. 27. L. lat. 65. L. transv. 5/11.
Large teeth in the lower jaw, on the vomer and the palatine bones. The height of the body is contained six times and four-fifths in the total length; the length of the head three times and two-fifths; the length of the caudal six times. The width of the interorbital space is more than the extent of the snout, and two-ninths of the length of the head. Cleft of the mouth wide the maxillary not extending to the vertical from the posterior margin of the eye (in old specimens it probably reaches to below that margin). There are eleven series of scales between the eye and the angle of the præoperculum; scales on the upper surface of the head of moderate size. The pectoral extends to the origin of the anal fin, and its length is less than one-half of that of the head: the ventral is not much shorter than the pectoral; greenish-olive, with darker streaks along the series of scales; a light longitudinal band from the eye to the middle of the caudal fin; two series of alternate darker blotches, one above the light band, the other below; side of the head with three oblique brown bands; dorsal and anal fins with oblique blackish stripes; caudal with blackish spots: the lower side of the head blackish, with white spots. (Günth., Fishes, iii., p. 476.)
7. Mastacembelus argus.
D. 32/60. A. 3/56.
Præoperculum with two or three spines. The maxillary does not extend to the vertical from the anterior margin of the eye. Vertical fins continuous: brownish-black, with white bands and round white spots: a band from the occiput, along the middle of the back, passing into the white margin of the vertical fins: a second band above the eye, interrupted and lost on the side of the back: a third from the angle of the mouth, passing into a series of spots, which is continued to the caudal: another series of spots along the side of the belly; the soft dorsal with a series of six spots: pectoral black at the base and near the margin. (Günth., Fishes, iii. p. 542.)
8. Cynoglossus xiphoideus.
D. 120. A. 98. V. 4. L. lat. 135.
Three lateral lines on the left side, the upper and lower separated from the middle by twenty or twenty-one longitudinal series of scales: a single line on the right side. Two nostrils: one between the posterior parts of the eyes, the other in front of the lower eye. Eyes separated by a concave space, the width of which is more than that of the orbit; the upper eye considerably in advance of the lower: lips not fringed. The length of the snout is contained twice and a third in that of the head, the angle of the mouth being behind the vertical from the posterior margin of the eye, and nearer to the gill-opening than to the end of the snout. The rostral hook terminates below the front margin of the eye. The height of the body is contained four times and two-thirds in the total length, the length of the head five times and a half. The height of the dorsal and anal fins is two-sevenths of that of the body. Uniform brownish-grey. (Günth., Fish., iv. p. 495.)