202 BULLETIN 18 8, UNITED STATES NATIONAL MUSEUM 



and four very short spinus gill rakers on the lower arm of the first 

 gill arch on each side. 



Referred to this species are 21 specimens collected by Deignan Sep- 

 tember 2 and 4, 1935, in Meklang Pla, a tributary of the Meklong, on 

 Doi Angka, Northern Thailand. These specimens range in size from 

 9.4 to 17.5 cm., the largest a male with strongly developed sharp 

 tubercles on the snout; a female with large ovaries and also bearing 

 large tubercles on the snout is 14.4 cm. long. In the important char- 

 acter of number of scales in the lateral line, these specimens are about 

 equally divided into lots with 34, 35, 36, 37, and 38 scales, a greater 

 number than in any of the numerous specimens of A. deauratus exam- 

 ined. Associated with this character is the possession by 16 of the 

 21 specimens of a greater number of predorsal scales than is found 

 in A. deauratus. Other distinctive features in A. hantamensis are the 

 relatively more slender caudal peduncle and the absence in the fully 

 adult fish of the black longitudinal bands on the caudal lobes. 



The scale characters in A. hantamensis compared with those in 

 A. deauratus are brought out in the following table based on 21 speci- 

 mens of the former and 39 specimens of the latter from five Siamese- 

 Indo-Chinese localities, namely, Koh Chang, in the Gulf of Siam; 

 the Mun Eiver in Eastern Thailand, and Huey Nam Puat in Laos, 

 both tributary to the Meklong ; the Pasak River in Central area ; and 

 Huey Meklong Kha, a tributary of the Salwin in Western region. 



