FAMILY, I— SILURID^. 491 



Lengtli, of head 6i, of candal 6, height of hody 7 to 9 in the total length. Eyes — small, situated in the 

 anterior 2/6 of the head. Mouth wide, lower jaw somewhat the longer. Barbels — nasal as long as the head, 

 and equalling the internal mandibular pair, the maxillary reach the end of the pectoral spine, whilst the outer 

 mandibular ones are not quite so long. Fins — dorsal not so high as the body, and situated in the commence- 

 ment of the second fifth of its total length, its spine about half as high as its rays, all are partly enveloped in 

 skin, as are also those of the anal. Adipose dorsal low, the length of its base equalling that of the rayed fin, 

 and two-thirds of the interspace between the two fins. Pectoral scarcely extending half way to the base of the 

 venti^l, which latter does not reach the anal. Caudal deeply forked, its upper lobe the longer. Caudal 

 peduncle as high as long. Lateral-Une — absent. Aw^essel — ^has a small rounded lobe on either side of the body 

 of the second vertebree, and all but a small portion of its front surface enclosed in bone. Colours — olive-brown, 

 lightest beneath. In some a dark line commences opposite the opercles, and soon subdivides : one branch going 

 to the centre of the base of the caudal, the other to the base of the anal. 



Hamilton Buchanan observes it is found in the Pumiah district. A. tenmspinis, Blyth, appears to be the 

 young, Jerdon brought the specimen from Ghazeepore. A. cceeutiens, Blyth, came from Pegu and Moulmein. 

 A. Kwzii, Day, appears to be a specimen which has been placed in too strong spirit, which has entirely altered 

 its appearance, however a figure is given. 



Habitat. — I have taken it at Klangra on the Himalayas and received it from Darjeeling. It is found in 

 the Jumna for some considerable distance from the Hills, also through Burma to Moulmein. It does not 

 appear to exceed 5 inches in length. When captured it bites most viciously, and lives for some time after its 

 removal from the water. ^ 



Genus, 24 — Sisoe, Hamilton Buchanan. 



Branohiostegals four. Oill-openings narrow and chiefly lateral, the gill-membranes being confluent with the 

 shin of the isthnms. Head and a/nterior portion of the trunk broad and depressed. Eyes small. Mouth small, 

 transverse, the upper jaw the longer. Nostrils rovmd and approximating, but separated by a valve, they are situated 

 midway between the eye amd the end of snout. One maxillary pair of barbels with broad bases, and about five 

 momdibulanr pairs. Teeth absent. A short dorsal fm destitute of a distinct spine : pectoral with a strong spine. 

 Ventral homing seven rays, and situated below the last portion of the dorsal fln. Anal with six rays. Caudal with 

 its upper ray very prolonged. Avr-vessel enclosed m a bony capsule. An axillary pore. 



Geographical distribution. — Indus and upper portions of the Jumnarand Ganges rivers. 



SYNOPSIS OP INDIVIDUAL SPECIES. 



Sisor rhabdophorus, D. i, A. 6. Indus, Jumna, and Ganges in their upper portions. 

 Sisor rhabdophorus, Plate CXV, fig. 1, la, lb. 



Ham. Buch. Fish. Ganges, pp. 208, 379 ; Bleeker, Beng. en Hind. p. 60 ; Gray and Hard. 111. Ind. Zool. ; 

 Swainson, Fishes,, ii, p. 305 ; Giinther, Catal. v, p. 262. 

 Chennuah, Hind. ; Kvr-ri-dee, Sind. 



B. iv, D. 1/6, P. 1/8, Y. 7, A. 6 (f ), C. 11. 



Length of head 6|, of caudal 11, height of body 11 in the total length excluding the caudal filament, 

 which in some specimehs equals the length of the body. %es— small, nearer the gill-opening than the end of 

 the snout, pupil transversely oval, with an extensible muscular flap (a part of the iris) on its upper edge as in 

 the Genus Platycephalus (see p. 274). Snout rather pointed. Median longitudinal groove on the head reaches 

 the base of the occipital process. The greatest width of the head equals two-thirds of its length. Numerous 

 rough ridges exist on the head, which is covered by very thin skin. There is a slight interspace between the 

 end of the occipital process and the basal bone of the dorsal fin, which last has an anterior and two lateral 

 processes covered with rough ridges. Mouth small, transverse, inferior, the upper jaw the longer. Barbels— 

 the maxillary reaclji the pectoral spine, and are dilated at their bases. From the lower lip there is a sort of 

 flap, having a rather long barbel at either side, which reaches the gill-opening : and two more intermediate but 

 shorter ones : between these flaps are several short barbels on a transverse line across the chin. There are five 

 plates on either side of the base of the dorsal fin, behind which the back has six elevated scale-hke plates along 

 the median line, the last forms a spine before the vertical from the anal fin. The last 1/2 o± the body is 

 covered by 12 osseous rings, having a superior and on either side a sharp edge as is seen m the pipe-hshes. 

 The lateral-Hne has also a series of smaller but rough bony plates. .Fms— dorsal rather higher than long, its 

 undivided ray weak, finely serrated anteriorly. Pectoral spine compressed, not quite so long as tUe head 

 serrated on both edges, but mostly strongly so on the external one. Ventrals arise under the posterior dorsal 

 rays. The anal commences behind the vertical from the spine on the back. Upper caudal ray with a long 

 prolongation. Golou/rs — blackish above, lighter below. j. • j-i, -uj 



In dissecting a smfl,U specimen (the only one I could spare) no air-vessel was apparent m the abdomen, 

 but two long bony capsules were present in the same situation as in the other fishes with an air-vessel tnus 



enclosed, and they also probably contained them. „ „ 



O R 4 



