igiQ- ! N. Annandale : Bombay Stream'; Fauna. 131 



head, but no specimens of this form are at present in Calcutta 

 The only species known from the Malay Archipelagjo is D. horneen- 

 ns, Vaillant, which has larger scales than any Indian species. 



Key to the Asiatic forms of Discognathus at present described. 



I. No barbels. L.L. 44 ... ... ... D. imhevhis. 



II. Two barbels. L.L. 38-40 ... ... * ... D. variabilis. 



III. Four barbels. L.L. 28 ... ... D. borneensis. 



IV. Four barbels. L.L. 32-36. 



A. Pectoral fins entirely horizontal, with their rays 



broad and flat ; chest flat, without scales. 



1. Pectoral fins longer than head, their tips 



extending nearly to base of ventrals ... D. mncrochir. 



2. Pectorals hardly longer than head, their 



tips not approaching the base of the ven- 

 trals ... ... ... ... D. nasittiis. 



B. Pectoral fins set obliquely on the sides of the 



body ; chest conve.x, with scales. 



I. Pectoral fins longer than head, their tips 

 approaching the base of the ventrals ; eye 

 much nearer margin of opercle than tip 

 of snout ; 2nd dorsal fin-ray slender ... D. gravelvi. 

 2 Pectoral no longer than head, not approach- 

 ing base of ventrals ; eye near middle of 

 head ; 2nd dorsal fin -ray stout. 



a. Posterior barbels longer than ante- 



rior ; pectorals directed backwards 

 and upwards, arising some distance 

 from ventral surface .. ... D. lamta var. 



rufiis. 



b. Barbels subequal, anterior pair usual- 



ly a little longer ; pecfCVals directed 

 backwards and a little downwards, 

 arising immediately above ventral 

 surface. 



i. Length'ofc head 5 to 5J times 

 in total length ; dorsal pro- 

 file convex in adult male ... D. latnta (s.s.) 

 ii. Length of head 6 to 6J times 

 in total length ; dorsal pro- 

 file nearly straight in adult 

 male ... ... D.jerdoni. 



Discognathus lamta (Ham. Buch.), Day. 

 (Plate II, figs. I, \a). 



1841. Chondrostoma mullya, Sykes, Trans. Zool.Soc. London, II, p. 359. 

 1889. Discognathus lamta, Day, Faun. Brit. Ind. Fish., I, p. 246, fig. 87. 

 1909. Discognatlius lamta, Jenkins, Rec. Ind. Mus., Ill, p. 291 (in part). 

 1913. Discognathus lamta, Annandale, Journ. As. Soc. Bengal, (n.s.) IX, 



p. 36, fig. I. 

 1918. Discognathus lamta, id., Rec. Ind. Mus., XIV, p. 45. 



The form to which I give this name is certainly the D. lamta 

 of Day, but there is some doubt as to whether Buchanan's 

 Cyprinus lamta was not rather the form called D. modestus by Day 

 and Platycara nasuta by McClelland. In any case, as the point 

 cannot be settled satisfactorily, it is best to accept Day's nomen- 

 clature so far as D. lamJa is concerned. 



