542 M.\STACEMI5JCTJD.T<:. 



4, Mastacembelus unicolor. 



Mastacombelu3 unicolor, (Ku/d C)- v. Ilass.) Cur. Sr Veil. viii. p. 4.J-? ; 

 Bleek. Verhand. Jiatav. Genootsch. xxiii., Notac. p. 5. 



D. 33-34 I 80-84. A. 3 | 75-81 . 



The vertical fins are distinct from one another and only continuous 

 at the base. Brownish above, yellowish below ; sides with large ob- 

 long light-coloured spots ; vertical fins brownish, edged with yelloAV ; 

 pectorals with two brown cross-bands. 



Java. 



5. Mastacembelus erythrotaenia. 



Bleek. Verh. Batav. Genootsch. xxiii., Notac. p. 6, and Borneo, I. p. 10. 

 D. 34-37 I 70-75. A. 3 j 71. 

 The maxillary does not extend to the vertical from the anterior 

 margin of the eye. Vertical fins continuous. Black or brown, with 

 four more or less irregular red longitudinal bands, the second of 

 which commences at the angle of the mouth ; vertical and pectoral 

 fins black, with red margin. 

 Rivers of Borneo. 



a. Adult. Borneo. Named M. (/iganteris. 

 h. Adult. Borneo. Named M. pictus. 



6. Mastacembelus argus. 



D. 32 I 60. A. 3 I 56. 



Prajoperculum with two or three spines. The maxillary does not 

 extend to the vertical from the anterior margin of the eye. Ver- 

 tical fins continuous. Brownish-black, with white bands and round 

 white spots : a band from the occiput, along the middle of the back, 

 passing into the white margin of the vertical tins ; a second band 

 above tlie eye, interrupted and lost on the side of the back ; a third 

 from the angle of the mouth, passing into a series of spots, which is 

 continued to the caudal ; another series of spots along the side of the 

 belly ; the soft dorsal with a series of six spots. Pectoral black at 

 the base and near the margin. 



Fresh waters of Siam. 



a. Fine specimen. Siam. From M. Mouhot's Collection. 



The appendage of the snout is trilobed, and shorter than the cleft 

 of the mouth. No notch is visible between the vertical fins. 



inches, lines. 



Total length 9 



Length of the head (with appendage) .... 1 9 

 Length of the tail (from vent) 3 



7. Mastacembelus armatus. 



Macrognathus armatus, Lacep. ii. p. 280 ; Buck. Ham. Fish. (lanq. 



pp. 28, mi. pi. .37. fig. 6. 

 Rhynchobdella polyac.intha, Bl. Sehn. p. 479. 

 Mastacembelus armatus, Cuv. ^ Val. viii. p. 45(>. pi. 240; ? Si/kes in 



