FRESH-WATER FISHES OF SIAM, OR THAILAND 203 



ACROSSOCHEILUS SCHROEDERI, new species 

 FlQtmE 35 



Description. — Moderately elongate and compressed ; depth of body 

 3.4 in standard length; least depth of caudal peduncle 1.5 in its length, 

 1.9 in length of head; eye 3.5 in head, slightly less than snout and 

 bony interorbital space ; mouth small, slightly overhung by snout, its 

 width at base about equal to diameter of eye ; lips rather full, postlabial 

 grooves of lower jaw approaching rather closely to each other and 

 leaving an isthmus 0.3 diameter of eye; maxillary not extending 

 beyond vertical from nostrils; barbels subequal, 1.5 times diameter 

 of eye. 



Squamation: Scales in lateral line 34; scales in transverse series 

 from midline of back to base of ventral fin 5.5 — 1 — 3 ; predorsal scales 

 11 ; circumpeduncular scales 16. 



--^-^^ 



Figure 35.—Acrossocheilus schroederi, new species: Type. Drawn by Mrs. Aime M. Awl 



Fins : Origin of dorsal fin over base of ventrals and nearer to tip of 

 snout than to base of caudal fin ; dorsal rays iii, 9 ; last simple dorsal 

 ray rather short and coarsely denticulated, its length less than head ; 

 caudal fin forked for more than 0.5 its length, about as long as head ; 

 anal fin small, rays iii, 5, longest ray 0.5 head; ventral fins 1.7 in 

 length of head, not reaching anal opening; pectoral rays i, 15, some- 

 what longer than ventrals. 



Coloration (in alcohol) : Plain; each scale of back and sides with a 

 narrow black basal crescent; a narrow but well-defined black line 

 from upper angle of gill opening to upper base of pectoral fin ; outer 

 part of dorsal rays and membranes blackish, giving the appearance 

 of a black spot when fin is partly flexed ; other fins plain. 



Type.— The type, 11 cm. long, taken in the Mekang on Doi Angka, 

 ^iorthern Thailand, in April 1937, by the Harvard Primate Expedi- 



