242 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



In the mountainous region between the headwaters of the Menain 

 Mun and the Menam Sak, where this species abounds, it is known to 

 the inhabitants as pla hok. 



LOBOCHEILUS QUADRILINEATUS (Fowler) 



Tj/lognathus quadril meatus Fowlee, 1935a, p. 124, figs. 67, 68 (Srisawut, Khao 

 Nam Poo). 



The type from Srisawat was 25.8 cm. long. Other specimens from 

 the type locality and from Khao Nam Poo were 7.5 to 18.3 cm. long. 

 In the Mekong, a tributary of the Meping south of Chiengmai, the 

 fish was found to be common in February 1932, browsing on algae 

 growing on rocks in the clear, shallow water; many specimens pre- 

 served were 11.9 to 18.3 cm. long. The fish was also common in the 

 Mekang, at Pang Chao, at the base Doi Angka, in December 1928. 



The species is characterized by a very small head (4.4 to 5.4 in 

 standard length), origin of dorsal fin far in advance of ventrals, all 

 scales on upper part of body with a black basal pocket, and four black 

 stripes on back and side posterior to the dorsal fin. 



LOBOCHEILUS TRANGENSIS (Fowler) 



Tylognathus travgensis Fowler, 1930, p. 72, figs. 19, 20 (Trang). 



Known only from the type, 13,7 cm. long, from a waterfall stream 

 near Trang, in Peninsular Thailand, this species is very close to 

 L. qiiadrilineatus (Fowler) and may prove a variant thereof. The 

 apparent differences are a more slender form (depth 4 as against 3 to 

 3.8 in L. quadrilineatus) , more depressed snout, and the presence on 

 the caudal peduncle of a blackish blotch, which extends on the base 

 of the median caudal rays. Several other differences mentioned by 

 Fowler do not seem to be valid; thus, trangevsis, instead of having 

 a "greatly longer pectoral fin" than Z, qiiadriUneatus, contained 1.25 

 times in head, in reality has a shorter pectoral than quadrilineatus 

 of which description and figure (Fowler, 1935a) show the pectoral 

 to be 1 to 1.12 in head; and L. trangensis, said to differ in having "but 

 4 scales below lateral line to ventral origin," in this feature agrees 

 essentially with quadriUneatus, described as having four or five such 

 scales and figured as having four. 



LOBOCHEILUS CORNUTUS, new species 



Figure 44 



Description. — Depth about 3.8 in standard length; least depth of 

 caudal peduncle about 0.5 its length and slightly less than 0.5 length 

 of head ; head 4 in length, its width at opercles slightly less than its 

 depth and more than 0.5 its length ; snout broad, blunt, its length less 

 than half head, thickly beset with large horny tubercles occupying 



