486 PHTSOSTOMI. 



snout and the hind edge of the opercle : the width of the gape of the month equals 1/3 of the total length of the 

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

 head, the anterior oblong and reaching forwards to between the middle of the eyes : the posterior oval and 

 commences 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. Ba/rbels — the nasal reach to the base of the 

 occipital process : the maxillary to the end of the pectoral spine : the mandibular ones are shorter. Teebh—ihose 



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



the width of the premaxillary band. Fims — 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 length of the head, rough externally, 

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

 brown, vertical fins edged with red. 



This fish appears to take the place of 0. magwr in Assam, and I have procured it from Goalpara and as 

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



Habitat. — Upper and lower Assam. 



Genus, 18— SACCOBEAifCHUS, Cwvier^amd Valenciennes. 



Hetero^neustes, Miiller. 



Bramchiostegals semen. Oill-openmgs wide, the membranes not being confluent with the shin of the isthmus, 

 and separated by a deep notch. Qill comity hamng am, accessory posterior sac, which extends backma/rds on either side 

 of the neural spines amongst the muscles of the abdominal and pa/rt of the caudal region. Head depressed, covered 

 with very thin shin : mouth transverse. Eyes with a free ci/rcula/r ma/rgin. Barbels eight. Teeth present in the jams 

 and on the vomer. Dorsal fm short and spineless : ventral with six ra/ys situated under the dorsal. Anal long a/nd 

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

 anterior vertebra, where it is enclosed by bone, a duct passes upwards from either side of' the a/i/r-vessel, unites, a/nd 

 opens into the inferior surface of the pharyrm. 



Geographical distribution. — Fresb waters of India, Ceylon, Burma, 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. 



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

 deemed by the Brahmins to be impure. 



SYNOPSIS OF SPECIES. 



A. Anal fin united to the caudal. 



1. SaccobroMchus microps, D. 8, A. 70. Eyes smaU. Ceylon. 



B. Analfm sepa/rated from the ca/udal by a notch. 



2. 8accobraMchusfossilis,'D.6-i,K.&Q-79. India and Burma. 



A. Anal fin umited 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. Hyes—umch. smaller than in S.fossilis, and 

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

 the root of the ventral fin. Teeth— ila.e vomerine band is interrupted in its centre. J'ms— origin 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. 

 CoZows— brown. 



Habitat. — Ceylon, to 6 inches in length. 



B. Anal fin separated from the ca/wdal by a notch. 



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



Sihirus fossilis, Bloch, t. 370, f. 2; Bl. Schn. p. 386 ; Swainson, Fishes, ii, p. 306. 



loo. ^fZ^^f '"^K'"' ■^*™- ^''°^- ^''^- <^anges, pp. 147, 374, pi. 37, f. 46 ; Taylor, Gleanings in Science, June, 



io?2' P' n. ^°'^ *^® air-bladder); Wyllie, Proc. Zool. Soc. 1840, p. 34; Hyrtl, Sitz. Akad. Wiss. Heft. 2, 



1853, p. 306 (on the circulation, etc.) 



o^« ^«,cco6mwc^«« singio, Cuv. and Val. xv, p. 400, pi. 448 ; Bleeker, Beng. p. 58 ; Kner, Novara Pische, 

 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 the amphibious nature of these fishes, p. 439. 



