118 TELEOSTEI. P11YSOSTOMI. 



surface of the head very finely shagreened and covered with thin 

 skin ; two depressions on the head the anterior oblong and reaching 

 forwards to between the middle of the eyes ; the posterior oval 

 and commencing midway between the posterior end of the anterior 

 fossa and the end of the occipital process, which latter is rounded, 

 and twice as broad at its base as it is long. Barbds the nasal 

 reach to the base of the occipital process, the maxillary to the end 

 of the pectoral spine, the mandibular are shorter. Teeth those 

 on the vomer globular and arranged in two pyrifortn bands, the 

 widest end internal and exceeding the width of the premaxillary 

 band. Fins pectoral reaches to below the commencement of the 

 dorsal fin and halfway to the base of the ventral, its spine strong, 

 one third of the total length of the head, rough externally, serrated 

 internally. Ventral reaches anal. Vertical fins not confluent 

 with the caudal. Colour greenish brown, vertical fins edged with 

 red. 



This fish appears to take the place of 0. mayur in Assam, and I 

 have procured it from Goalpara and as high as Sadiya. Its teeth 

 distinguish this from other species or possibly varieties. 



Hab. Upper and Lower Assam. 



Fifth group. SILUEINA. 



7. Genus SILUBUS, Artedi. 

 Syn. Parasilurus, pt., Bleeker. 



Dorsal profile nearly horizontal ; head covered with soft skin. 

 Gill-openings wide, the gill-membranes not confluent with the skin 

 of the isthmus, and deeply notched. Mouth transverse. Eyes 

 without free orbital margins, situated above the level of the angle 

 of the transversely placed mouth. Nostrils remote from one 

 another. Barbels six (Silurus, Bleeker) ; or four (Parasilurus, 

 Bleeker) ; one pair being maxillary, and one or two pairs mandi- 

 bular. Teeth cardiforra or villiform in the jaws, in one or two 

 transverse bands on the vomer, none on the palatines. One very 

 short and spineless first dorsal but no adipose fin ; anal terminates 

 close to the caudal, but is not usually continuous with it ; ventrals 

 situated posterior to the dorsal, and consisting of eight or more 

 rays. Air-bladder not enclosed in bone. 



Geographical Distribution. Eastern Europe, Central and South- 

 eastern Asia. In India and Burma this genus is represented in 

 the ghats on the Western coast ; along the Himalayas from 

 Afghanistan to Darjeeliug, also in the hills above Akyab and the 

 Tenasserim provinces, in Cochin China and beyond. These fishes, 

 so far as I know, have not been recorded from waters of the plains 

 of India. 



