FRESH-WATER FISHES OF SIAM, OR THAILAND 507 



The species is small. The largest examples observed locally have 

 been 11.5 cm, long. 



A vernacular name, apparently applied to no other species, is pla hu 

 klet kheng (hard-scale goby) . 



Genus PRIONOBUTIS Bleeker 



Prionobutis Bleekee (453), Arch. N^evl. Sci. Nat., vol. 9, p. 305, 1874. (Type, 

 Eleotris dasyrhynchus Giinther.) 



PRIONOBUTIS KOILOMATODON (Bleeker) 



Eleotris koilomatodon Bleeker, 1849 (15), p. 21 (Surabaya and Kammal). 

 Prionobntis koilomatodon Fowlee, 1937, p. 248, fig. 259 (Paknam, Tachin). 



This fish, ranging from India through the Indo-Australian Archi- 

 pelago to the Philippines and China, is almost exclusively a salt-water 

 form, but may be noticed here because of its reported occurrence in 

 the lower Menam Chao Phya and lower Tachin Kivers. A specimen 3.3 

 cm. long was collected by Layang Gaddi November 27, 1929, near Pak 

 Jong, in headwaters of the Menam Mun in Eastern Thailand, and 

 another specimen 2.6 cm. long was taken by the writer March 17, 1930, 

 on Koh Chula, a rocky islet off the Chantabun Estuary in Southeastern 

 Thailand; and in both of these specimens the supraorbital ridge is 

 very strongly serrated. Herre (1927, p. 52) found the fish several 

 kilometers up the Pasig Kiver near Manila. 



A length somewhat over 10 cm. is attained. 



Genus OPHIOCARA Gill 



Ophiocara Gnx, Proc. Acad. Nat. Sci. Pliiladelpliia, 1863, p. 270, 1864. (Type, 

 Eleotris ophiocephalus Cuvier and Valenciennes.) 



OPHIOCARA POROCEPHALA (Cuvier and Valenciennes) 



Eleotris porocephala Ctjviee and Vaxenciennes, 1837, vol. 12, p. 237 ( Seychelles ; 



New Ireland). 

 Ophiocara porocephala Smith. 1934b, p. 325 (Chantabun Estuary, Paknam Wain, 



Koh Chang, Patani, Singora). 



This species has a wide distribution in the Indian and Pacific 

 Oceans. Thailand is well within its range and has yielded many 

 specimens from both fresh and salt waters, although there are few 

 published records of its occurrence. In addition to the localities in 

 Southeastern and Peninsular Thailand, noted above, specimens were 

 taken in October 1927 in the Patani River at Yamoo by Masya and 

 Suvatti, of the Siamese Bureau of Fisheries. 



The maximum size recorded for local specimens is 21 cm. for a fish 

 from the Paknam Wain River May 21, 1931. 



