24 The Ganoids 
For the group here called Lepidostei numerous other names 
have been used corresponding wholly or in part. Rhombo- 
ganoidea of Gill covers nearly the same groups; Holoste: of 
Miller and Hyoganoidea of Gill include the Halecomorphi also; 
Ginglymodt of Cope includes the garpikes only, while £theo- 
spondylt of Woodward includes the Aspidorhynchide and the 
garpikes. 
Fig. 14.—Semionotus kapffi Fraas, restored. Family Semionotide. 
(After Fraas, per Nicholson.) 
The Semionotide (Stylodontide) are robust-bodied Ganoids, 
having the vertebree developed as rings, the jaws with several 
rows of teeth, those of the outer row styliform. 
Semtonotus bergert is a well-known species, with the body 
moderately elongate. Semzonotus agassizi and many other species 
occur in the Triassic of the Connecticut valley and in New 
Jersey. The body is very deep in the related genus Dapedium, 
and the head is covered with strong bony plates. Dapedium 
politum is a well-known species of the English Triassic. Tetra- 
gonolepis (Pleurolepis) is a similar form, very deep and com- . 
pressed, with strong, firm scales. 
In the extinct family of Lepidotide the teeth are conical or 
chisel-shaped, while blunt or molar teeth are on the inside of 
the mouth, which is small, and the suspensorium of the mandible 
is vertical or inclined forward. The body is robust-fusiform, 
covered with rhomboid scales; the vertebrze form rings about 
the notochord; the teeth are either sharp or blunt. The dorsal 
fin is short, with large fulcra. 
The best known of the numerous genera are Lepidotes, 
rather elongate in body, with large, blunt teeth. Of the many 
species of Lepidotes, Lepidotes elvensis abounds in the English 
