451 
Family AMPHIPNOTDAE 
Opercle .and subopercle extended posteriorly into very 
thin membranous plates. Gills present only on second branchial 
arch. Accessory breathing apparatus present, diverticula of 
the pharynx on each side of vertebral column above gills between 
skull and pectoral arch. Humeral arch not connected with skull. 
Vertebrae.171, of which 65 caudal. Scales present. 
S' 
Fresh and brackish waters of tropical asia. These fishes 
are noted for their accessory respiratory air sac which commun¬ 
icates with the gill cavity. These organs are two small blad¬ 
ders similar to the hind parts of the lungs in serpents. They 
function by being filled immediately with air derived from the 
atmosphere. Externally when inflated they appear as two round¬ 
ed protuberances. These fishes are truly amphibious and when in 
the water constantly rise to the surface to take in air. At 
times they have been found lying in the grassy sides of ponds, 
similar to the habit of snakes. 
