FRESH-WATER FISHES OF SIAM, OR THAILAND 473 



made in all parts of Thailand. The explanation may lie in the rarity 

 of the species or in the failure of collectors to recognize it or to 

 distinguish it from other species. Giinther made no comparison 

 with related forms, and his description falls far short of present-day 

 requirements. The type, 44 lines (7.4 inches) long, is in the British 

 Museum, and the original description is as follows : 



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 praeoperculum ; 

 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. 



Dr. Ethelwynn Trewavas, of the department of fishes of the British 

 Museum, has by request examined the type and has kindly indicated 

 the peculiarities of the lateral line, as follows : 



In the type of Ophiccphalus siamensis the lateral line runs nearly straight 

 to the 14th (left) or 16th (right) perforated scale. The drop to the lower 

 row involves the 15th to 20th (left) or 17th to 20th (right), and from here 

 onwards the line continues to the caudal. At the drop an anterior row of 

 scales seems to taper out, so that a continuation backwards of the anterior 

 part of the lateral line would lie in the scale-row above the posterior, but a 

 continuation forwards of the posterior part would lie two rows below the 

 anterior. 



OPHICEPHALUS MICROPELTES Cavier and Valenciennes 



OpJiicephalus micropelfes Cltvier and Valenciennes, 1831, vol. 7, p. 427 (Java). — 

 Fowler, 1934a, p. 150 (Chiengmai). 



Ophicephalus serpentinus CtJviER and Valenciennes, 1831, vol. 7, p. 429 (Siam). 



Oi)hiocephalus mici-opeltes Gunther, 1861, vol. 3, p. 482 (Siam). — Bleeker, 1865 

 (347), p. 36 (Siam); 1865 (3.j6), p. 174 (Siam).— Saxjvage. 1881, p. 160 

 (Siam) ; 1883b, p. 151 (Menam Chao Phya). — Weber and de Beaufort, 1922, 

 vol. 4, p. 328 (Siam).— Hora, 1923b, p. 181 (Nontaburi).— Vipulya, 1923, p. 

 223 (Bangkok). 



Ophiocephalus stevensi Bleeker, 1865 (356), p. 174 (Siam). — Sauvage, 1881, p. 

 160 (Siam). 



Ophiocephalus mlcropeltis Karoli, 1882, p. 171 (Siam). 



Channu micropcltes Fowler, 1937, p. 224 (Kemarat). 



Wliile inhabiting all parts of Thailand this fish is primarily an in- 

 habitant of the larger streams and canals. Its range includes also 

 Indo-China, Malaya, the East Indian islands, Burma, and India. 



