CHAPTER XXII 



TELEOSTEI (CONTINUED ): SYMBRANCHII APODES HAPLOMI 



HETEROMI CATOSTEOMI PERCESOCES ANACANTHIXI 



Sub- Order 3. Symbranchii. 



EEL-SHAPED Fishes without paired fins, with the pectoral arch 

 free or suspended from the skull, and with the anterior vertebrae 

 distinct, without Weberian ossicles. Gill-openings confluent into 

 a single, ventral slit. Air-bladder absent. 



The structure of the skull conforms to that of typical Malaco- 

 pterygians. The praemaxillary and maxillary are well devel- 

 oped, the latter placed behind the former, and forming but a very 

 small part of the oral border ; the symplectic is present ; the 

 parietals form a long sagittal suture, and separate the frontals 

 from the supraoccipital. The vertebrae are very numerous, the 

 praecaudal bearing very strong parapophyses, to which short, 

 slender ribs are attached. The skin is naked (Symbranchidae) or 

 covered with minute scales (Amphipnoidae), and the vertical fins 

 are rudimentary, reduced to mere dermal folds. 



Like the Apodes, which they resemble in general appearance, 

 these Fishes are no doubt derived from some low type with 

 abdominal ventral fins, but whether from the Malacopterygii 

 or the Haplomi we have as yet no data from which to conclude. 

 Only two families are known. 



Fam. 1. Symbranchidae. Post- temporal well developed, 

 forked, attached to the skull. Inhabitants of- the fresh or 

 brackish waters of South-Eastern Asia, Tropical America, Australia, 

 and Tasmania. Three genera are known: Symbranehtts, with 

 two species from India and the Malay region, and one from 

 Central and South America ; Monopterus, with a single species 



597 



