FRESH-WATER FISHES OF SIAM, OR THAILAND 575 



entering the lower courses of rivers. Two specimens of this species 

 from Thailand in the British Museum were presented by Prince 

 Chumporn. A single specimen, 7.5 cm. long, taken at Yamoo on a 

 branch of the Patani Kiver, Peninsular Thailand, October 12, 1927, 

 is U.S.N.M. No. 109685. There seem to be no other Thai records. 



The species G. patoca is characterized by having the dark back and 

 top of head thickly covered with small round white spots, the lower 

 parts silvery. Immature specimens, like the one from Yamoo, often 

 show three or four dark cross bands extending from the back to the 

 middle of the side. 



A length of 30 cm. or somewhat more is attained. 



Bleeker listed as Chelonodon dumeHli, new species, a fish collected 

 in Thailand by Bocourt, referring to it as "restent a decrire." In a 

 second paper issued in the same year the fish appears as Chelonodon 

 dumerili Bleeker without comment. No description of the species 

 was ever published, there are no further references to it in the litera- 

 ture, and this name has no standing. It is suspected that the fish 

 Bleeker had was Chelonodon patoca. 



Genus TETRAODON Linnaeus 



Tetraodon Linnaeus, Systema naturae, ed. 10, p. 332, 1758. (Type, Tetraodon 

 Uneatus Linnaeus.) 



This genus of numerous marine and estuarine fishes has several 

 representatives in Thailand as in other Oriental countries that occur 

 in fresh water. 



Compared with the marine species, the fresh-water forms are of 



small size. 



The vernacular name of all these fishes in Thailand is pla pah pao. 



In addition to the species given in the following key, there are sev- 

 eral others, specimens of which have been noted as coming from the 

 fresh waters of Thailand but which cannot be conclusively accepted 

 as to identification. Among these are: (1) Tetraodon hispidus Lin- 

 naeus, a specimen 17 cm. long, March 2, 1924, from Chiengrai, on the 

 Mekok, a tributary of the Mekong. This specimen, called pla Mom 

 pah wong, agreed well with the descriptions and figures of this well- 

 known species, differing only in minor features. As Chiengrai is 

 over a thousand miles from the sea and this species is not otherwise 

 known from fresh water, the identification must be considered doubt- 

 ful. The specimen is not available for further examination. (2) 

 Tetraodon iminaGulatus Bloch, in Schneider. Four specimens 5.8 to 

 8.3 cm. long are reported by Fowler (1937) as coming from Kemarat, 

 Eastern Thailand, several hundred miles up the Mekong. No descrip- 



