552 TELEOSTEI CHAP. 
of the breeding habits and development in this important family. 
To the late J.S. Budgett we owe some very interesting observations 
made in the Gambia on Gymnarchus niloticus! The Fish makes 
a floating nest, emerging on three sides, over which the male 
keeps a fierce watch ; the recently-hatched larvae are remarkable 
for the enormous size of the yolk-sac, which hangs down, acting 
as a sort of anchor, and for the presence of long external branchial 
filaments, as in Selachian embryos. The Fish propels itself 
through the water entirely by the action of its dorsal fin, forwards 
and backwards with equal facility; when swimming rapidly 
Fic. 332.—Gymnarchus niloticus. i nat. size. 
backwards, it may be seen to use the end of its tail as a feeler 
to guide the way. Budgett has also identified, with some doubt, 
the eggs of Hyperopisus bebe, out of which emerged embryos not 
unlike those of some tailless Batrachians, which hung suspended 
to rootlets of grass in swamps by means of threads of viscid 
mucus secreted from glands on the top of the head. 
Fam. 8. Hyodontidae.—Margin of the upper jaw formed by 
the praemaxillaries and the maxillaries, the latter the more devel- 
oped and firmly united to the end of the former. Parietal bones 
separating the supraoccipital from the frontals; a large hole on 
each side of the skull, between the parietal, the squamosal, and 
the epiotic (paroccipital), closed by a large, thin, bony plate (the 
supratemporal), which extends over the greater part of the 
parietal; suboperculum and interoperculum small, the latter 
partly hidden below the praeoperculum. Basis cranii double. 
Jaws, palatines, pterygoids, vomer, parasphenoid, and glossohyal 
toothed; no pharyngeal teeth. Ribs sessile, inserted above and 
behind well-developed parapophyses; epineurals, no epipleurals. 
1 Trans. Zool. Soc. xvi. 1901, p. 126. 
