CHAPTER XXII 
TELEOSTEI (CONTINUED Ns SYMBRANCHII——A PODES——-HAPLOMI— 
HETEROMI——CATOSTEOMI— PERCESOCES——ANACANTHINI 
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. Guill-openings confluent into 
a single, ventral sht. 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: Symbranchus, with 
two species from India and the Malay region, and one from 
Central and South America; Monopterus, with a single species 
597 
