244 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



Type and paratypes.—T\i& type (U.S.N.M. No. 107957) 17.3 cm. 

 long is a male collected by R. Havmoller in February 1929, in Klong 

 Chawang, a mountain stream east of Bandon, Peninsular Thailand. 

 Four other specimens with the same data in the National Museum 

 collection are 16.3 to 20.2 cm. long, all with marked development of 

 rostral pearl organs and all with the dorsal and anal fins having con- 

 spicuous dermal flanges. Paratypes are U.S.N.M. Nos. 108100, 109773, 

 117627, 117636, 119524. 



Other specimens. — Other material, also collected by Mr. Havmoller^ 

 was taken in December 1929, from Klong Sok, a tributary of the 

 Menam Tapi, Peninsular Thailand ; one is a male 19.5 cm. long, with 

 large rostral tubercles divided into upper and lower groups by a 

 deep horizontal groove, which is continuous around the front of the 

 snout; the other is a female 19 cm. long, with no tubercles but with 

 small pores on the front of the snout. 



Remarks. — This form is as yet known only from mountain streams 

 in the Bandon district of Peninsular Thailand. It is distinguished 

 chiefly by its moderately elongate form ; single pair of short maxillary 

 barbels ; large, elliptical, freely movable padlike superficial part of the 

 lower lip ; and exuberant development of rostral tubercles with a deep 

 horizontal sulcus dividing the tubercles into two groups. Charac- 

 teristic are the dark longitudinal stripes on the posterior part of the 

 body, with the middle stripe most strongly defined. Full sexual 

 maturity is attained by the males when they are about 16 cm. long. 



This fish has a general resemblance to Loho'cheilus quadrilineat'us^ 

 described by Fowler from North-Central Thailand, and may prove 

 to be a local variety or race thereof. Fowler's description and figures 

 indicate differences in the general shape of body, shape and size of 

 head, shape and length of snout, and other minor characters. The 

 present form has a less elevated back, more slender caudal peduncle, 

 longer head, more posterior position of the eyes, together with the 

 marked rostral sulcus, which appears to be lacking in L. quadri- 

 lineatus, even in specimens that are of much larger size than is known 

 to be attained by L. cornutus. 



LOBOCHEILUS CRYPTOPOGON (Fowler) 



Tylognathus cryptopogon Fowler, 1935a, p. 125, figs. 69, 70 (Khao Nam Poo) ; 

 1935b, p. 513 (Old Chiengsen). 



Known from a few specimens, 6.8 to 10.4 cm. long, from the lOiao 

 Nam Poo, Central Thailand and the Mekong at Old Chiengsen, North- 

 ern Thailand. The dorsal fin, with a sharply defined black edge, 

 arises well in advance of the ventrals over the ninth scale of the 

 lateral line; the short maxillary barbels are concealed in the post- 

 labial groove; the lower lip is coarsely fringed; the body is marked 



