THE EELS AND THEIR ALLIES 



2823 



of which lie the maxillae. The paired fins are rudimental, and the vertical ones 

 wanting; while the scales, if present, are minute; and accessory breathing organs 

 may be developed. An air bladder is wanting, the stomach has no blind append- 

 age, and the ovaries are furnished with ducts; the vent being situated far behind 

 the head. Whereas the majority of these eels inhabit fresh and brackish waters in 

 tropical Asia and America, they are also represented in Australia, where one genus 

 is marine. Of the fresh-water forms, the most remarkable is the amphibious eel 

 (Amphipnous cuchia) of Bengal, in which there is an accessory breathing appa- 

 ratus, the body is scaled, and the pectoral girdle is detached from the skull. There 

 are only three gill arches with rudimentary laminae, separated from one another by 

 narrow slits; and the additional breathing organ takes the form of a lung-like sac 

 on each side of the neck communicating with the gill chamber. Day states that 



BENGAL SHORT-TAILED EEL. 

 (One-fifth natural size. ) 



"this amphibious fish, when kept in an aquarium, may be observed constantly 

 rising to the surface for the purpose of respiring atmospheric air direct. It usually 

 remains with the snout close to the surface, and in like manner lies in the grassy 

 sides of ponds and stagnant pieces of water, so that without trouble it may obtain 

 access to air. ' ' Indeed , the chief respiration of this fish is carried on by means of 

 the two sacs on the sides of the neck, which can be inflated and emptied at will. 

 In the other two fresh-water genera, one of which (Monopterus} is confined to the 

 Oriental region, while the other {Symbranchus) has a distribution coextensive 

 with that of the family, there is no additional breathing organ, the body is naked, 

 and the pectoral girdle is attached to the skull. Whereas in the former of these 

 genera the gills are rudimental, in the latter they are well developed; and, in the 

 absence of an accessory apparatus, it seems strange how the one species with rudi- 



