486 PHYSOSTOMI. 



snout and the hind ed^c of the opcrcle : the width of the gape of the month equals 1/3 of the total length of the 

 liead. Upper surface of the head very finely shagreened and covered with thin skin : two depressions on the 

 licad the anterior oblono' and reaching forwards to between the middle of the eyes : the posterior oval and 

 oommences midway between the posterior end of the anterior fossa and the end of the occipital process, which 

 latter is rounded and twice as broad at its base as it is long. Barbels — the nasal reach to the base of the 

 occipital process : 'the maxiUary to the end of the pectoral spine : the mandibular ones are shorter. Teeth— ihoae 



on the vomer in two pyriform bands ^i^, of globular ones, the widest end being internal where it exceeds 



the width of the premasillary band. Fins — pectoral reaches to below the commencement of the dorsal fin and 

 1/2 way to the base of the ventral, its spine strong, 1/3 of the total len.gth of the head, rough externally, 

 serrated internally. Ventral reaches anal. Vertical fins not confluent with the caudal. Colours — greenish- 

 brown, vertical fins edged with red. 



This fish appears to take the place of G. magur in Assam, and I have procured it from Goalpara and as 

 high as Suddya. Its teeth distinguish this from other species or perhaps varieties. 



Eahlfat. — Upper and lower Assam. 



Genus, 18— Saccobkauchus, Ctwier and Valenciennes. 



Heteropneustes, Miiller. 



Branch'ostegals seven. Gin-openings wide, the memlranes not heing confluent with the sh'n of the isthmus, 

 and separated by a deep notch. Gill cavity having an accessory posterior sac, irhich extends bachwards on either side 

 of the neural spines amongst the muscles of the abdominal and part of the caudal region. Head depressed, covered 

 vnth very thin skin: mouth transverse. Eyes with a free circular margin. Barbels eight. Teeth present in the jaws 

 and on the vomer. Dorsal fin short and sjnneless : ventral with six rays situated under the dorsal. Anal long and 

 confluent with or separated from the caudal by a notch. Air-vessel* placed _ transversely across the bodies cf the 

 anterior vertebra, where it is enclosed by bone, a duct passes upwards from either side of the air-vessel, unites, and 

 opens into the inferior surface of the pharynx. 



Geographical distribution. — Fresh waters of India, Ceylon, Bm-ma, and extending to Cochin China, but 

 not found in the Malay Archipelago. Being amphibious (see p. 439) they can live long after their removal from 

 the water. 



XJggs_ — Considered exceedingly wholesome and invigorating by the natives of India, but in some places 

 deemed by the Brahmins to bo impui-e. 



SYNOPSIS OF SPECIES. 



A. Anal fin ^mited to the caudal. 



1. Saccobranchus microps, D. 8, A. 70. Eyes small. Ceylon. 



B. Anal fin separated from the caudal by a notch. 



2. Sacco5r(Mtc7ms/oMi7ts, D. 6-8, A. 60-79. India and Burma. 



A. Anal fin united to the caudal. 



1. Saccobranchus microps. 



Giinther, Catal. v, p. 31. 



D. 8, P. 1/6, A. 70. 



Length of head 7|, height of body 8 in the total length. Eyes — much smaller than in S. fossiUs, and 

 less than 1/3 in the length of the snout. 'Barbels — the nasal ones reach the end of the pectoral : the maxillary 

 the root of the ventral fin. Teeth — the vomerine band is interrupted in its centre. Fins— origm of the dorsal 

 is 2/7 of the length (excluding the caudal fin) from the end of the snout. Pectoral spine feebly serrated, 

 two thirds as long as head. Ventral fin reaching the anal, which last is united with the caudal. 

 Colours — brown. 



Habitat. — Ceylon, to 6 inches in length. 



B. Anal fin separated from the caudal by a notch. 

 2. Saccobranchus fossilis, Plate CXIV, fig. 1. 



Silurus fossiUs, Bloch, t. 370, f. 2; Bl. Schn. p. 38G ; Swainson, Fishes, ii, p. 306. 



Silurus singio. Ham. Buch. Fish. Ganges, pp. 147, 374, pi. 37, f. 46 ; Taylor, Gleanings in Science, June, 

 1830, p. 170 (on the air-bladder); Wyllie, Proc. Zool. Soc. 1840, p. 34; Hyrtl, Sitz. Akad. Wiss. Heft. 2, 

 1853, p. 305 (on the circulation, etc.) 



Saccobranchus singio, Cuv. and Val. xv, p. 400, pi. 448 ; Bleeker, Beng. p. 58 ; Kner, JS'ovara Fische, 

 p. 302; Gunther, Catal. v. p. 30 ; Day, Proc. Zool. Soc. 1869, p. 612, Fish. Malabar, p. 198. 



Silurus laticeps, and biserratus, Swainson, Fishes, ii, p. 306, 393. 



* See remarks on tlie amphibious nature of tbese fishes, p. 439. 



