FRESH- WATER FISHES OF SIAM, OR THAILAND 71 



the progress of incubation. On July 12, 1931, the observer named 

 discovered a school of young swamp eels at the surface in shallow 

 water, and nearby, projecting from a hole in the soft bottom, he saw 

 the head of an adult eel, supposed to be the female parent. The young, 

 numbering several hundred, were in a compact mass 20 to 25 cm. wide, 

 and when some of them were scooped up in a coconut shell the adult 

 made no attempt to defend them but withdrew into the hole. The 

 young were of a pale brownish color, with the upper part of the body 

 and head thickly beset with minute dark brown spots. A dark line 

 extended from the eye to the snout, and a dark stripe extended down- 

 ward and backward from the eye. The average length of 29 specimens 

 was 33.6 mm. ; the range being from 27 to 36.5 mm. 



This eel is caught in considerable quantities for domestic consump- 

 tion and local sale, and at times shipments are made to the Bangkok 

 markets. It bears transportation well, as it is able to live out of water 

 for a long time if its skm is kept moist. 



The fish seems to have no distinctive vernacular names but shares 

 with other eels the name fla lai. 



Family SYNBRANCHIDAE 



Two Thai representatives of this family of eellike fishes fall into 

 two genera, as follows : 



la. Gill openings narrow, forming a single aperture confined to the ventral sur- 

 face ; posterior nostrils oval, above eye ; eyes small ; origin of dorsal fin in 

 advance of anal opening Synbranchus 



1&. Gill openings forming a single, very v?ide aperture extending up sides to lateral 

 line ; posterior nostrils oblique, lanceolate, above eyes ; eyes minute ; origin 

 of dorsal fin opposite anal opening Macrotrema 



Genus SYNBRANCHUS Bloch 



Synbranchus Bloch, Naturgeschichte der auslandischen Fiscbe, vol. 9, p. 86, 1795. 

 (Type, Synbranchus marnioratus Bloch.) 



SYNBRANCHUS BENGALENSIS (McClelland) 



Ophisternon bengalensis McClelland, 1845, p. 197, pi. 11, fig. 1 (Bengal). 

 Symbranchus bengalensis Karoli, 1882, p. 184 (Siam). — Boulenger, 1903, p. 303 



(Patani River). 

 Synbranchus bengalensis TVebek and de Be-vufort, 1916, vol. 3, p. 41G, fig. 213 



(Siam).— HORA, 1923b, p. 174 (Bangkok). 



The range of this fish extends from India through the Indo- Austral- 

 ian Archipelago to the Philippines, French Indo-China, and Thailand. 

 It is apparently rather rare in Thailand, and the only specimens ob- 

 served in recent years have been three recorded by Hora (1923b) from 

 Bangkok and one collected in the Menam Chao Phya at Nontaburi on 

 September 26, 1924. The occurrence of the fish in Peninsular Thailand 



