GTMNAECHUS. — NOTOPTEEID.E. 145 



skin connects the gill-openings across the isthmus. Dorsal 183-230. 

 Pectoral rounded, ^ to f length of head. Scales very small, largest 

 along the middle of the side. Olive or brown above, whitisli beneath, 

 end of tail blackish. 



Total length 1070 millim. 



Upper Nile to Bahr-el-Ghazal, Lake Rudolf, Chad Basin, Senegal, 

 Gambia, Niger. — Type in Paris Museum. 



Fam. 3. NOTOPTERID^. 



Margin of the upper jaw formed by the prsemaxillaries and the 

 maxillaries, the latter the more developed; parietal bones separating 

 the supraoccipital from the frontals ; a large hole on each side of the 

 skull, between the squamosal, the exoccipital, and the epiotic ; sym- 

 plectic present; no suboperculum ; interoperculum small, hidden under 

 the preeoperculum. No pharyngeal teeth. Eibs sessile ; accessory 

 bones (adpleurals) attached to the extremity of the anterior ribs, with 

 which they may be fused, and embraced by ossifications forming a 

 double ventral serrature ; praecaudal vertebra? with transverse processes 

 in front of the ribs. Pectoral fins folding against the sides of the body. 

 Air-bladder communicating with the ear. No oviducts. 



Fresh and brackish waters of S.E. Asia and Tropical Africa. 



Two genera : — 



Dorsal fin present 1- Notopterus, Lacep., p. 146. 



No dorsal fin 2. Xenomyi^ius, Gthr., p. 147. 



VOL. I. ^ 



