FRESH- WATER FISHES OF SlAM, OR THAILAND 



149 



CYCLOCHEILICHTHYS TAPIENSIS H. M. Smith 

 FiGUBE 21 



CpclochelUchthys tapiensis Smith, 1931a, p. 11, fig. 5 (Tapi River, Bandon Bight). 



This fish is known from six specimens collected in September 1923 at 

 several places on the Tapi Kiver and in Bandon Bight off the mouth of 

 that river in the Gulf of Siam. 



The type is 13 cm. long, and the largest of the examples examined is 

 16 cm., which represents about the maximum size attained, according 

 to the local fishermen. 









Figure 21. — Cyclocheilichthys" tapiensis H. M. Smith. Dra.vn by Luang Masya; courtesy 



of the Thailand Governmet. 



The species is not very strongly separated from C. dumerilii as inade- 

 quately described by Sauvage and as described in greater detail by 

 Fowler with a number of points of difference. The two forms may 

 perhaps be separated by the following characters : A depression i\t the 

 nape in C. tapiensis, none in C. dv/merilii; interorbital space concave 

 and equal to diameter of eye in former, convex and 1.3 to 1.5 times di- 

 ameter of eye in latter; lines of sensory pores include conspicuous 

 longitudinal groups on snout and cheek in former, while in latter all 

 the lines are said to be transverse ; 5 rows of scales between the lateral 

 line and the ventral base in G. tapiensis, 4 in C. duTnerilii; fourth sim- 

 ple dorsal ray scout and with 13 antrorse teeth in former, slender 

 with 24 antrorse teeth in latter ; and caudal peduncle with a more or 

 less conspicuous round dark spot in former and none in latter. 



The names by which the fish is called are pJa Icamprad (slippery 

 fish) , pla fa, and pla fa hin. 



590087—45 11 



