624 TELEOSTEI CHAP. 
In Halosaurus the scales of the lateral line, which runs near 
the lower profile, are scarcely enlarged, and are destitute of 
luminous organs. Halosaurichthys differs in the union of the 
ventral fins with each other, as in Notacanthus. In Halosauropsis 
the scales of the lateral line are strongly enlarged and pouch- 
like, and bear photophores. 
This family is one of great antiquity, being represented in 
the Upper Cretaceous of Westphalia by Ecehidnocephalus, which, 
as shown by A. 8. Woodward, appears to have been closely 
related to Halosaurus. 
Fic. 379.—Halosauropsis macrochir, 3 nat. size. (After Giinther.) 
Fam. 3. Lipogenyidae.—Similar to the preceding in shape 
and in the position of the dorsal fin, but with a toothless, 
roundish, inferior, suctorial mouth, and with the short dorsal and 
the long anal formed partly of spines and partly of soft rays. 
Head and body covered with minute scales; lateral line nearer 
the dorsal than the ventral profile. Ventrals with 3 spines and 
7 soft rays. A single species, Lipogenys gillii, from the North 
Atlantic, 865 fathoms. 
a 
Fic. 380.—Lipogenys gillii. (After Goode and Bean.) 
Fam. 4, Notacanthidae.—Body elongate, covered with very 
small cycloid scales, the tail tapering to a point, without caudal 
fin; head scaly; mouth small, inferior, bordered by the prae- 
maxillaries only; jaws toothed; no suborbitals; praeopereulum 
small; post-temporal replaced by hgament. Dorsal fin formed 
of a series of short disconnected spines; anal very long, formed 
partly of spines and partly of soft rays, extending to the end 
of the tail. Ventrals with 1 to 5 spines and 7 to 10 soft 
rays. 
