80 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 





Figure 3. — Oula caeruleostigmata (H. M. Smith). Drawn by Luang Masya; courtesy of 



the Thailand Government. 



on the side between the head and the dorsal fin, and the blue spots dis- 

 appeared. Specimens had previously been obtained in an outlet of 

 Bung Borapet near Paknampo in November 1923, and in the main river 

 near Chainad in December 1924, 



CHELA MOUHOTI, new species 

 FIGUBE4 



Description. — Depth 2.25 in standard length; least depth of caudal 

 peduncle less than 2 in head and about equal to length of peduncle; 

 dorsal profile nearly straight from tip of snout to point of middle of 

 back, thence a gentle convex curve to origin of dorsal fin ; ventral profile 

 markedly and regularly decurved from mouth to base of caudal, its 

 lowest part at ventral fins; head small, sharp, about 4 in standard 

 length; mouth very small, strongly oblique, tip of lower jaw on level 

 with pupil, posterior end of maxillary at lower level of pupil ; ej^e about 

 3 in head, equal to interorbital space and longer than snout. 



Squamation: scales in lateral line 31 (including 3 or 4 non-tube- 

 bearing scales in pectoral axil), in transverse line 7-1-5 or 6, in pre- 

 dorsal region 20, around caudal peduncle 14. 



Fins: Dorsal origin over anal origin, two-thirds distance from tip 

 of snout to last scales on caudal base, dorsal rays iii,10, first branched 

 ray shorter than head less snout, edge of fin straight ; caudal forked, 

 much longer than head ; anal rays iii,23, margin slightly incised, longest 

 branched ray about equal to longest dorsal ; ventrals more than half 

 length of head; pectorals equal to depth of body and 1.75 length of 

 head, reaching to anal. 



