492 PHTSOSTOMI. 



Habitat.— Bind, Ganges and Jumna rivers in NortHem India, Bengal, and Behar, attaining 8 feet or more 

 in length. It is not Tincommon at Delhi. It is only eaten by the lowest and poorest classes. It is said to lie 

 under stones when young. 



Genus, 25— Gagata, Bleeher. 



Batasio* pt. Blyth : Callomystax, Giinther. 



Bramchiodegals five to seven. Gill-openings rather narrow, the gill-membramss lemg confluent with the shm 

 of the isthmus. Thorax smooth. Upper surface of the head with sharp longitudinal ridges, amd covered hy thin shin. 

 Eyes subcutaneous. Snout overhoMging the mouth. Nostrils close together, the anterior rownded, the posterior being 

 provided with a vahe and usually with a barbel. Barbels eight, one nasal (sometimes rudimentary), one maxillary, 

 and two mandibular- pairs a/rising on a tramsverse line behind the chin, and usually with stiff bases. VilUform teeth in 

 jaws : palate edentulous. First dorsal with one spine amd six or seven rays : adipose of moderate length. Pectoral 

 spine strong. Ventral with six rays situated posterior to the dorsal fin. _ Anal with a moderate (11-13) number of 

 rays. Caudal forked. Air-vessel im two rownded portions, each of which is enclosed im, am, osseous cup. 



Geographical distribution. — Eivers of Sind, India, (except Madras) and Burma. 



SYNOPSIS OF SPECIES. 



1. Gagata cenia, D. i, A. 14-16. Six barbels and a rudimentary nasal pair. Copper coloured, with dark 

 blotches and banded fins in the young : dull gray, with black fins in the adult. Indus, Jumna, and Ganges 

 rivers with their aifluents, also Orissa, Assam, and Burma. 



2. Gagata itehkeea, D. i A. 12-14. Eight barbels. Copper coloured, with dark blotches. Deccan. 



3. Gagata batasio, D. f, A. 16. Eight barbels. Body with two dotted stripes. Testa. 



4. Oagata tengana, D. -f, A. 14. Eight barbels. A dark blotch above the pectoral fin, another on the 

 crown of the head. Dorsal and caudal dotted, edges nearly black. Assam. 



1. Gagata cenia, Plate CXV, figs. 4 (adult), 5 (young). 

 Pimelodus gagata. Ham. Buch. Eish. Ganges, pp. 197, 379, pi. 39, f. 65 ; Bleeker, Bengal, p. 58 (adult). 

 Pimelodms cenia. Ham. Buch. 1. c. pp. 174, 376, pi. 21, f. 57 ; Bleeker, Beng. en Hind. p. 58 (yoimg). 

 Gagata typus, Bleeker, Ned. Tyds. Dierk.-1863, p. 90 ; Day, Proc. Zool. Soc. 1869, p. 309. 

 Callomystax gagata, Giinther, Catal. v, p. 218. 

 Heinipimelodus cenia. Day, Proc. Zool. Soc. 1869, p. 308. 

 Jungla, Bengali : Genia, Sind. : Nga-nan-jovng, Burmese. 



B. v-vi, D. -v/0, P. 1, V. 6, A. 14-16 (rff^), C. 19. 



Length of head 4| to 6, of caudal 4| to 5, height of body 5 to 7 in the total length. Eyes — diameter 

 4 to 4j in the length of head (3 in the young), 1 to 1| diameters from the end of snout, and 1 apart. Head 

 1/4 higher than wide : snout somewhat compressed, overhanging the mouth. The median longitudinal groove 

 on the head deep, and extends to the posterior end of the occipital process, which is narrow and almost touches 

 the basal bone of the dorsal fin. Barbels — nasal rudimentary : the m.axillary pair reach to the base of the 

 pectoral spine, or a little more : the two mandibular pairs arise on a transverse line across the chin, the outer 

 are half as long as the head. Fins — the dorsal higher than the body, its two first rays being the longest, spine 

 moderately strong, as long as, to 1/4 longer than, the head :f it is serrated anteriorly in its upper fourth in the 

 young. Pectoral reaches to above the ventral, its spine is stronger, longer or shorter than that of the dorsal, it 

 is strongly denticulated internally, serrated externally in its outer fourth. Base of the adipose dorsal as long as 

 that of the rayed fin. Air-vessel — in two lateral portions, enclosed in bony capsules. Colours — dull gray, the 

 outer two-thirds of the pectoral, the outer halves of both dorsals, ventral and anal black : caudal whitish. The 

 young are of a yellowish bronze colour, becoming silvery on the abdomen : they have three dark bands over the 

 head, and four more over the back, descending as low as the lateral-line. Caudal with a semilunar black band, 

 or a black blotch on each lobe : a dark mark across the dorsal fin. 



Some small fry from DarjeeUng show the lower half of the front surface of the dorsal spine rough. 



Habitat. — Rivers of Bengal and Orissa, the Jumna, Ganges, and Indus, also Burma. It attains a foot in 

 length. The specimen (fig. 4) was from Calcutta, where it is very common, (fig. 6) is from a Delhi example. 



2. Gagata itehkeea, Plate CXV, fig. 6. 

 Phraetocephahis itehkeea, Sykes, Trans. Zool. Soc. ii, p. 373, t. 67, f. I. 

 Bagrus itchJteea, Bleeker, Beng. p. 56. 

 Pimelodus itehkeea, Jerdon, M. J. L. and Science, 1849, p. 341. 



• Genus Batasio, Blyth, is said to comprise fishes with the barbels shorter than the head and teeth on the palate, examples : 

 PimelodMS batasio, H. B. (the author merely says of the teeth, that those " in both jaws are crowded"), P- tmgana, H. B. B. affimis, 

 Blyth, P. chcmd/ramara, H. B. and P. rama, H. B. The two first probably belong to Genus Oagata, the third to Maerones, and the last 

 two to Liocassis. 



t This alteration with age is very well shown in a series of these fishes, specimens from 2 to 3 inches long hare the dorsal 

 spine from 7 to 7^ in the total length : from 3 to 4 inches the spine is 6 to 7 : from 4 to 5 inches the spine is 5 to SJ times : from 5 to 

 6 inches the spine is 5 to 5 J times. 



