12 SYMBEANCHIDiE. 



Fam. 27. SYM BRANCH ID.^. 



SymbrancHi, Mutter, Ahhandl. Ak. Wiss. Berlin, 1846, p. 193. 



Body elongate, naked or covered with minute 

 scales; baibels none. Margin of the upper jaw 

 formed by the intermaxillaries only, the well-deve- 

 loped maxillaries lying behind and parallel to them. 

 Paired fins none. Vertical fins rudimentary, reduced 

 to more or less distinct cutaneous folds. Vent situated 

 at a great distance behind the head. Ribs present. 

 Gill-openings confluent into one slit situated on the 

 ventral surface. Air-bladder none. Stomach without 

 csecal sac or pyloric appendages. Ovaries with ovi- 

 ducts. 



Fresh waters and coasts of Tropical America and Asia. Coasts of 

 Western Australia and Van Diemen's Land. 



Synojasis of the Groups and Genera. 



A. Amphipnoina. Vent in the posterior half of the length. 



Humeral arch not attached to the skull. 



Palatine teeth in a single series ; an accessory breathing-sac. 



1. Amphipnous, p. 13. 



B. SrMBRANCHiNA. Vcut in the posterior half of the length. 



Humeral arch attached to the skull. 

 Palatine teeth in a narrow band ; gills rudimentary ... 2. Monopterus, p. 14. 

 Palatine teeth in a band ; gills well developed 3. Symhranchui, p. 15, 



C. Chilobranchina. Vent in the anterior half of the length. 

 No teeth on the palate 4. Chilobranchus, p. 17. 



Osteological MemarJcs. 



The following remarks are made on the skeletons of 



Vertebra;. 



AmpMpnous cuchia 106 + 65 



Monopterus javanensis 100 + 88 



Symbranchus marmuratus 79 + 57 



Si/mbranehus bengalensis 80 -|- 53 



(^Chilobranchus dorsalis) 21 + 52 



The skull of the Symbranchidoe is distinguished by solid, firmly- 

 united bones, especially those of the temporal region being much 



