732 Records of the Indian Museum. [Vol. XXII, 



elongate snout it closely resembles certain species of the genus 

 Homaloptera, hut it can be readily distinguished by the absence 

 of barbels and by the presence of a free air-bladder in the abdom- 

 inal cavity. 



Buchanan found the species in " the rivers of Northern 

 Bengal," while his second species, P. halitora, was "found in the 

 rivers towards the north-east of Bengal." McClelland [op. cit.), 

 who had examined only a single specimen of P. balitora for 

 warded to him from "Upper Assam" by Capt. Hannay, gave 

 the habitat of both the species as " north-eastern parts of Bengal." 

 Giinther [op. cit.) who followed ^McClelland made the same mistake. 

 The specimens of P. balitora in our collection enable me to con- 

 firm Buchanan's statement tlrat the species occurs in the Khasi 

 Hills (north-east of Bengal), while P. sucatio is found at the base 

 of the Darjiling Himalayas (Northern Bengal;. I ' referred some 

 j'oung specimens collected by Dr. Annandale at Siliguri in the 

 Mahanadi River to P. balitora, but on further examination I find 

 that thej' are the young of P. sucatio. The mistake was due 

 to the immaturity of the specimens. 



The genus Psilorhynchus comprises three Indian species, 

 one of which was recently described by myself (op. cit.. p. 208) 

 from immature specimens found in the Naga Hills. The new 

 species is readily distinguished from those previously known by its 

 straight profile, by the absence of any grooves on the under surface 

 of the head and by the position of the eye, which is considerably 

 nearer to the tip of the snout than to the posterior limit of the 

 operculum. P. sucatio differ; from P. balitora in possessing a long 

 depressed snout and a greatly elevated back fin. 



x^nnandale '' described a species of fish from the Bombay Presi- 

 dency under this genus, but quite recently I ^ have referred it to a 

 separate genus for which I have proposed the name Parapsilo- 

 rhynchus. 



In Psilorhynchus sucatio the dorsal profile is greatly arched. 

 It is highest near the base of the dorsal fin, whence it slopes con- 

 siderably towards both ends. The ventral profile is only slightly 

 aiched. The caudal peduncle is narrow and elongated. The head 

 is much depressed and both the upper and the louer surfaces 

 are greatly flattened ; it is one and a quarter times as long as broad. 

 The length of the head is contained about 5 times in the length 

 of the body excluding the caudal fin. The depth of the body 

 in full grown specimens is slightly less than the length of the 

 head and is contained 5-5 times in the length of the body. 

 The snout is broad and evenly rounded ; the interorbital space is 

 somewhat concave. The eyes are large and globular and are situ- 

 ated in the posterior half of the head ; they are only slightly 

 visible from below. The diameter of the eye is contained almost 



■ Hor.i, Rer. Iiii. Mm. ,\IX, p. 210 (1920). 



- .\iiti,Tndale, Rec. Ind. Miis. XVI, p. 128 (igiQ' 



■' Hora, Rec. hid. Miis. XIX, p. 209 11920). 



