112 MASTACEMBELIDit:. 



Suborder IX. O P I S T H O M I. 



Air-bladder without open duct. Operculum well developed, hidden 

 under the skin ; supraoccipital separating the parietals, in contact with 

 the frontal. Pectoral arch suspended from the vertebral column, far 

 behind the skull ; no mesocoracoid. Dorsal and anal fins with spines, 

 ventrals absent. 



Fam. 1. MxiSTACEMBELIM;. 



Body more or less eel-shaped ; a series of short spines detached from 

 the very elongate dorsal fin. Scales very small. Anterior nostril widely 

 separated from the posterior, and opening in a tentacle on each side of a 

 dermal rostral appendage. Mouth not protractile, bordered by the pra;- 

 maxillaries, to the upper border of which the maxillaries are attached. 

 Gill-opening inferior ; gills 4 ; branchiostegal rays 6 ; no pseudobranchife. 

 Vertebrae numerous (72-95), the prajcaudals with transverse processes 

 bearing the ribs. 



Fresh and brackish waters of Southern Asia and Tropical Africa. 

 A single genus in Africa. 



1. MASTACEMBELUS. 



Gronov. Zoophyl. p. 133 (1781), part.; Giintli. Cat. Fish. iii. p. 540 (1861); 

 Bouleng. Poiss. Bass. Congo, p. 490 (1901), Fish. Nile, p. 540 (1907), and 

 Journ. Ac. Philad. (2) xv. 1912, p. 197. 



liostral appendage not striated inferiorly. Dorsal with 7 to 39 spines, 

 anal with 1 to 3. 



South-eastern Asia, China, Euphrates, Oxus, and Tropical Africa. 



In all the African species the caudal fin is confluent with the dorsal 

 and anal. 



Synopsis of the Species. 



I. Vent equally or nearly equally distant from end of snout and from caudal 

 fin. 

 A. Less than 20 dorsal spines ; no prajorbital or prajopercular spines. 

 D. VII 105 ; A. in 70 ; length of head * 5^ 



times in total length 1. AI. paudspinis, Elgr., p. 115. 



D. XVIII 85 ; A. II 90 ; length of head 8§ 



times in total length 2. il/./rmai««, Blgr., p. 116. 



Tlie head is measured to the gill-opeuing, and tlie rostral appendage is not included. 



