FRESH-WATER FISHES OF SIAM, OR THAILAND 349 



the Ping Kiver at Raheiig, Chomtong, and Chiengmai ; the Kok River 

 at Chiengrai; Kwan Payao; the Pasak River; the Rangsit Canal; the 

 Bangpakong River at Prachin; the Klong River at Rajaburi; a small 

 stream on Koh Chang ; the Tadi Stream, Nakon Sritamarat ; the Tale 

 Sap; the Patani River; and the Seamreap River in Cambodia. 



The Deignan collection contains three adult albinos from the Meping 

 at Chiengmai and from a pond, connected with the river, at the Leper 

 Hospital near Chiengmai. Albinism is fairly common in this species. 



A maximum length of more than 40 cm. is attained. 



This fish, like other members of the genus, experiences no incon- 

 venience when kept out of water for a long time if the respiratory ap- 

 paratus remains moist. Drying of the gills and arborescent organs is 

 retarded by the small, tightly closed branchial openings. Sometimes 

 the fish voluntarily leaves the water, presumably in search of better 

 living or feeding conditions or perhaps to escape enemies. Move- 

 ments on land suggest swimming and can be properly described as 

 wriggling, hence the vernacular name. The flat head and extended 

 pectoral fins keep the fish in an upright position as it moves forward 

 by rapid lateral bendings of the tail. On August 13, 1926, a friend 

 brought the writer a fish that in the late afternoon of the previous day 

 was picked up on a metaled driveway in his yard in Bangkok. The 

 fish had left a small canal 15 meters away and was proceeding toward 

 another canal 35 meters away. It was placed in a flat jar of water in 

 the writer's office. It left the jar during the night (apparently by 

 jumping), dropped from a table to the floor, passed through a short 

 corridor, traversed a large exhibit room, went the entire length of a 

 long hallway, and was found in a lively condition just inside the front 

 door at 11 p. m. It was released the next morning, having earned its 

 freedom. 



As a food, the fish is very important in Thailand. Its flesh, which 

 is white, is popularly considered rather less nourishing than that of 

 C. macrocephalus. 



The local name is pla duk dain (dull-colored wriggling fish) ; and a 

 belief is widespread that this is the male of macrocephalus^ of which 

 the female is called pla duk uey. 



CLARIAS TEYSMANNI Blceker 



Clarias teysmanni Bleeker, 1857 (166), p. 344 (Tjikoppo, Buitenzorg Province, 

 Java).— HoEA, 1923b, p. 165 (Nakon Sritamarat).— Smith, 1934b, p. 290 

 (Klong Pong, Nakon Sritamarat). 



This species, known also from Ceylon, Malaya, Sumatra, Borneo, 

 and Java, has a very limited distribution in Thailand. It was first 

 recorded by Hora from a single specimen, 18 cm. long, taken in Feb- 

 ruary 1922 in the Nakon Sritamarat Mountains, Peninsular Thailand. 



