FRESH-WATER FISHES OF SIAM, OR THAILAND 237 



li" Genus LOBOCHEILUS van Hasselt 



Lohocheilus van Hasselt, Alg. Konst. Letterbode, vol. 2, p. 132, 1823. (Type, 

 Lohocheilus falcifer van Hasselt.) 



The lobocheilids are mostly inhabitants of swift waters, often moun- 

 tain brooks, but may frequent still waters, such as the Tale Sap. They 

 are vegetarians. Their long, regularly coiled intestine is nearly al- 

 ways crowded with algae and other aquatic plants cropped from stones 

 and logs. Feeding is facilitated by the sharp-edged, horny covering 

 of the lower jaw and the development of a large, freely movable 

 fleshy pad constituting the superficial part of the lower lip. 



There seems to be no valid reason why the name Lohocheilus should 

 not be used, in the sense exemplified by Bleeker (1863 (314) and 1863 

 (301), vol. 3), for fishes that conform with the generic characters of 

 van Hasselt's haplotype Z. falcifer. 



Bleeker, in various papers, credited the genus and the type species 

 to van Hasselt. Cuvier and Valenciennes (1842, vol. 16), however, 

 called van Hasselt's fish Labeo falcifer "nobis," without giving van 

 Hasselt credit for the earlier use of the specific name. Giinther (1868, 

 vol. 7, p. 65) called the fish Tylognathus falcifer^ credited the species 

 to Cuvier and Valenciennes, and placed Lohocheilus falcifer van Has- 

 selt in the synonymy. Weber and de Beaufort (1916, vol. 3) followed 

 Giinther and made no reference to van Hasselt. 



Following a detailed definition of the genus Lohocheilus, Bleeker 

 (1863 (301), vol. 3) wrote: 



The shape of the lips and jaws takes, in this remarkable genus, a character 

 quite special, in that the lower lip, which forms a free and rounded lobe, received 

 the upper lip only upon the posterior part of its upper surface. This arrange- 

 ment is met with again neither in the cyprinoids nor in any other family of 

 fishes. Although this character suffices quite well to distinguish this genus, one 

 can add to it the simple form and the thickness of the lower jaw, the form of the 

 postlabial groove, the absence of rostral lobes and of labial papillae, etc. 



The use of the name Lohocheilus for certain Thai fishes will leave 

 the generic name Tylognathus of Heckel (1843) available for fishes of 

 this general form in which the lower lip is not provided with a con- 

 spicuous free superficial lobe. All of the local species have only maxil- 

 lary barbels; several species of the East Indies have both maxillary 

 and rostral barbels. 



In the present account, 12 local species are recognized, all but one 

 peculiar to Thailand. Several of them may be eliminated when more 

 material is available for examination and comparison. The species 

 may be differentiated as follows : ; r 



la. Body moderately elongate, depth 3 to 4 in standard length. 

 2a. Back and side without longitudinal stripes; head small, 4.6 to 4.9 in 



length; pectoral fins equal to or longer than head bo 



2&. A single dark longitudinal stripe or band along side; head 4 to 4.5 in 

 length ; pectoral flns less than head. 



