294 TELBOSTEI. PHYSOSTOMI. 



B.Jilameiitosus, C. V., with none. If a number of examples are 

 examined, it will be found that in some these appendages are 

 minute, the barbels being as a rule smallest in specimens obtained 

 furthest from the hills. In South Oanara, the Wynaad, and base 

 of the Nilgiris, where the barbels are large, the B. mahecola abounds ; 

 towards Cochin and up the Coromandel coast as far as Madras that 

 species is small or absent, and the B. filamentosus is the type. 

 Here, undoubtedly, the question must force itself on one's notice, 

 Are we dealing with two distinct species, or one in a state of 

 transition? The adults of Barbus punctatus and B. pliutunio are 

 often exactly similar, but in the immature form the first retains its 

 original colour, not so the second. Barbus chola and B. tetrarupurjus 

 are similar, except as to the presence of a black spot behind the 

 opercle in the latter ; whilst Barbus ticto shows considerable 

 variations. Great changes evidently occur in some species if they 

 are removed to another locality : thus Barbus conchonius, which has 

 been imported from the plains and introduced into the Naini Tal 

 lake, is evidently losing the serrature of its dorsal spine ; in time, 

 if this change goes on, the species will become more like B. torio 

 than the original form. 



The majority of those species which constitute the subgenus 

 Barbodes (4 barbels), provided they are soberly coloured, attain a 

 large size ; the brilliantly coloured forms are mostly residents in clear 

 and rapid mountain-streams or rivers contiguous to hills and are 

 generally small. A strong dorsal spine is usually (if not invariably) 

 a sign that the species lives in the vicinity of high mountains, up 

 the streams of which it ascends to breed ; an exception, however, 

 has to be made of those forms having serrated dorsal spines, and 

 which are usually residents of waters of the plains. Considerable 

 individual variations exist as to the comparative length and size of 

 the dorsal spine ; as a rule it increases in strength in the adult. 



Species of the subgenus Capoela (2 barbels) never attain the size 

 reached by many of the Barbodes ; some, more especially when 

 residing in mountain-streams, have vivid colours. The species of 

 the subgenus Puntius are mostly of small size ; a few are brilliantly 

 coloured. 



Geographical Distribution. Europe, and throughout Asia and 

 Africa. Eepresentatives of this genus exist in most, if not all, 

 Indian and Burmese rivers and tanks, the larger species being 

 generally termed Mahseers. Some attain an enormous size, as 

 much as 90 Ib. and upwards ; these are more frequently residents 

 in rivers along the bases of hills or in large rapids, but a few have 

 a more extended range. The number of species appears to di- 

 minish as the Malay Archipelago is approached, whilst those forms 

 having 4 barbels and also an osseous and serrated dorsal ray increase 

 largely in proportion to the others. 



