FRESH-WATER FISHES OF SIAM, OR THAILAND 79 



1822), and Perilampus is thus a synonym thereof. Bleeker in 1863 

 (314, p. 215) made Perilampus guttatus McClelland { = Chela laubuca 

 Hamilton) the type of Laubitca, which thus became a synonym of 

 Chela^ laubuca and cachius being congeneric. Giinther made Hamil- 

 ton's Chela atpar ( = <7. cachius) the type of Cachius^ which is also a 

 synonym of Chela as here defined. 



These are small fishes of streams and ponds in India, Burma, Ceylon, 

 Thailand, and Sumatra. None reaches a greater length than 10 cm., 

 and most of them are much smaller. The body is deep and greatly 

 compressed, the abdominal edge is cultrate, the mouth is terminal and 

 directed obliquely to vertically upward, the lateral line is deeply de- 

 curved and parallel with the ventral outline, the anal fin is many-rayed 

 and longer than the dorsal, the pectoral fins are long and pointed, and 

 the outer ray of the ventral fins is elongated. Three species have been 

 reported from local waters, differentiated as follows : 



la. Body very deep, its greatest depth 2.15 to 2.25 times in standard length ; anal 

 rays ii, 22 or ii, 23. 

 2a. Scales in lateral line 35, above lateral line 9, belovp lateral line to base of 

 ventrals 3 or 4, around narrowest part of caudal peduncle 12; a con- 

 spicuous bright blue spot on top of head, another in front of dorsal fin ; 

 4 to 9 short vertical blackish stripes above pectoral fin, a blackish-green 



spot on shoulder caeruleostig'inata 



26. Scales in lateral line 31, above lateral line 7, below lateral line to base of 

 ventrals 5, around narrowest part of caudal peduncle 14 ; no blue spots 

 On head and back ; no dark vertical stripes on side ; a conspicuous round 



blackish spot on shoulder mouhoti 



16. Body more elongate, its greatest depth 2.8 to 3.6 times in standard length; 

 scales in lateral line 32 to 37; in transverse line 6.5-1-2 or 3 to base of 

 ventrals ; anal rays ii, 17 to ii, 21 ; a blackish spot on shoulder, another at 

 base of caudal fin, these connected by a blackish line laubuca 



CHELA CAERULEOSTIGMATA (H. M. Smith) 

 FIGUBE 3 



Laubuca caeruleostigmata Smith, 1931a, p. 5, fig. 3 (Menam Chao Phya, Bung 

 Borapet). 



This dainty and strikingly marked little fish has been observed only 

 in the Menam Chao and tributaries in Central Thailand. It first came 

 in for special notice on January 5, 1925, when, by the use of a short- 

 handled dip net under the muddy bank of the river, near Nakon Sawan, 

 the writer caught in a short time 10 specimens somewhat over 6 cm. 

 long. Placed in a bucket of turbid river water, the fish were nearly 

 invisible even when close to the surface except for a bright caerulean- 

 blue area on the top of the head and another on the median line of the 

 back in advance of the dorsal fin. Immediately after being placed in 

 formalin, the specimens exhibited 4 to 9 short vertical blackish stripes 



