1910. | N. ANNANDALE: Fish from India and Persia. 69 
Baring, and channel leading out of the Hamun 12 miles east of 
Iab-i-Baring ; small watercourse, Lutak, southern Seistan. 
Habtts.—D. adiscus is gregarious and always lives in large 
shoals. In the day-time it stays at the bottom, feeding apparent- 
ly on algae, but in the evening I have seen shoals swimming on 
the surface. All the individuals we found in the Hamun, which 
were not numerous, were dead or dying, and we found enormous 
numbers in a moribund condition, in which they floated on the 
surface, in pools of very foul water in a stream-bed north of 
Nasratabad. We did not find the fish in any but still or slow- 
running water. 
I have placed this species in the genus Dzscognathus with 
some doubt, but I do not know where else to placeit. The mouth 
differs distinctly from that of both Cirrhina and Crossochilus, 
though the structure of the gill-openings resembles that found in 
these genera. Moreover, the mental disk, though poorly developed 
and differing in shape from that of other species, is present, and 
the general facies is not unlike that of D. quadrimaculatus. On 
the whole I think that the species must be accepted as an ex- 
tremely primitive representative of Discognathus. If this be so, 
its provenance, together with that of the other primitive species D. 
variabilis, D. phryne and I). wanae, would suggest that the genus 
perhaps originated in South Western Asia. It is noteworthy that 
it does not occur in Central Asia, and possibly the African species 
that are apparently allied, may be degenerate rather than primitive. 
Without examininig specimens I cannot express an opinion on 
this point. 
Discognathus wanae, Regan.! 
“Depth of body 4 in the length, length of head 44 to 42. Snout 
rounded, nearly as long as postorbital part of head; diameter of 
eye 5 in length of head; interorbital region flat, its width nearly 
4 length of head. Width of mouth + length of head; two barbels 
‘on each side, shorter than diameter of eye. Upper lip with 
minute papillae near the margin; lower very narrow; behind it a 
circular disc divided into a papillose anterior and a smooth pos- 
terior portion, and with only the posterior edge free. Dorsal III 7 ; 
origin equidistant from tip of snout and base of caudal; first or 
second branched ray longest, nearly as long as head. Anal II 5. 
Pectoral extending 2 of distance from its base to pelvics, which 
nearly or quite reach vent. Caudal deeply emarginate. Greyish, 
mottled with darker. 
“‘ Five specimens, the largest 80 mm. in total length.’’ (Tate 
Regan). Mr. Regan has kindly informed me that there are about 
36 scales in the lateral line and that both back and belly are 
covered with scales smaller than those on the sides. 
I have not seen this species, the description of which I quote 
in full. It was described from Waziristan in the hills of the 
! Tate Regan, Ann. Mag. Nat. Hist. (8) XIII, p. 263, fig. A (1914). 
