158 Records of the Indian Museum. [VoL. XVIII, 
Sind. They form a large proportion of that of Persia and are 
abundant in western Asia. In Seistan, however, only three species 
and two genera are known, and these are the only species (except 
possibly Schizocypris brucei) that are not of direct Central Asiatic 
ancestry. 
The two genera are Discognathus, Heckel (which we distin- 
guish from Garra, Ham. Buch.) and Scaphiodon, Heckel. Both 
these genera probably originated in south-western Asia, but 
whereas Scaphiodon has proliferated specifically in Baluchistan 
and has extended its range from southern Arabia southwards and 
eastwards through Mesopotamia and southern Persia, along the 
Mekran coast and through Sind to the Malabar Zone of Penin- 
sular India, Discognathus, of which only a few species are known, 
occupies a region extending from the North-West Frontier of India 
to Syria. Since or shortly before reaching India, however, it gave 
rise to a more highly specialized offshoot (Garra) which has sepa- 
trated into many species in the Peninsula and ranges, possibly 
from Syria! ts Borneo and southern China. Scaphiodon, Garra 
and probably Discognathus occur together in Oman. 
Genus Scaphiodon, Heckel. 
1878. Scaphiodon, Day, Fishes of India, II, p. 550. 
1913. Scaphtodon, Zugmayer, Abh. Wiss. K. Bay. Ak. (Math.-phys. 
Klasse), XXVI, p. 28. . 
The geographical distribution of this genus is peculiar. It 
seems to centre in Baluchistan, in which no less than six distinct 
species occur. Thence it extends westwards to Persia and southern 
Arabia and southwards through Sind down the Malabar Zone of 
Peninsular India and inland as far as the base of the Nilgiris. 
Zugmayer (op. cit.) discusses the species known from Balu- 
chistan and Seistan. 
Scaphiodon macmahoni, Regan. 
1906. Scaphiodon macmahoni, Regan, Fourm. As. Soc. Bengal, Ul, p.s. 
To facilitate reference we quote Mr. Tate Regan’s description 
of the species :—- 
“Depth of body 33 to 3+ in the length, length of head 4: to 
42. Snout obtuse, shorter than the post-orbital part 
of head. Diameter of eye 4 to 4: in the length of 
head, interorbital width 25,22. Mouth inferior; lower 
jaw with nearly straight transverse anterior edge; 
barbel originating directly below the nostril, shorter 
than the eye. Scales 37-392, 4 between lateral line 
! The systematic position of the Syrian Discognathus rufus, Heckel, pre- 
viously regarded by one of us asarace of D.lamta, Ham. Buch. is doubtful. 
No specimens are at present available to us, but the figure published in the 
Fournal of the Asiatic Society of Bengal (N.S.) IX, p. 37, fig. 2, suggests that 
the species is a true Discognathus (s.s.). 
