170 Records of the Indian Museum. [VoL. XVIII, 
Genus Schizothorax, Heckel. 
1888. Schizothorax, Herzenstein, Fische, p. 96, in Wiss. Res. Przewalski 
Central-As. Reis.,; Zool. (II (2). 
1916. Schisothorax, Vinciguerra, Ann. Mus. Civ, Stor. Nat. Genova, 
@), VALI spe 123- 
The genus is well represented in the Helmand system, whence 
Vinciguerra (loc. cit.) has given the names of the following five 
species :—S. brevis, McClell., S. macrolepis (Keys.), S. minutus, 
Kessler, S. ritchianus (McClell.), and S. zarudnyit (Nikolsky). There 
is also in the Indian Museum a mutilated skin from the old collec- 
tion of the Asiatic Society of Bengal labelled ‘‘ Schizothorax 
labiatus, McClell. Helmund R., Afghanistan.’’ The specimen is 
too imperfect to substantiate the identification, but the species to 
which it has been assigned is too distinctive to have been readily 
mistaken. We have thus six species known from this river- 
system, but except S. zarudnyi all these species have been found 
only in the upper waters at comparatively high altitudes. S. 
zarudnyt, moreover, is so closely allied to S. intermedius, McClell., 
a species common in some parts of the mountains of Afghanistan, 
that there can be little doubt as to its having originated as an 
isolated race of that species. 
Schizothorax zarudnyi (Nikolsky). 
(Plate Sk V5 figs: 1-2), 
1897. Apiostoma sarudnyt, Nikolsky, Ann. Mus. Zool. Ac. Sct., St. 
Petersburg, II, p. 346. 
1899. Schizothorax zarudnyt, id., ibid., IV, p. 409. 
This species is, as we have already stated, very closely allied 
to S. intermedius, McClell.,' but the following differential charac- 
ters are constant in a large series of adult specimens :— 
1. The paired fins are much smaller. 
The branchial isthmus is longer and narrower. 
The scales are slightly enlarged at the base of all the fins, 
especially the dorsal and the anal. 
Oo 
Among the races assigned to S. intermedius by Herzenstein 
S. zarudnyi comes nearest affinits, Kessler (op. cit., p. 113, pl. xiv, 
fig. 1), but the snout is more pointed and the paired fins smaller 
and there are no greatly enlarged scales behind the opercular 
border. 
These differences may seem to some ichthyologists of no more 
than racial value and we have already admitted that we believe 
S. zarudnyi to have originated from S. intermedius as a local race. 
The differences are, however, so constant that we consider it more 
convenient to regard the Seistan fish as now specifically distinct. 
The colouration varies with the environment. In muddy 
water the back and fins are pale olive-green, the sides faintly 
| Herzenstein (op. cit., p. 106) does not regard the form identified with 
McClelland's species by Day as the forma typica, but see Giinther, Cat. Fish. 
Brit. Mus. 
