374 
ACTINOPTERYGIT. 
Family PACHYCORMID/E. 
Trunk fusiform or elongate. Cranial and facial bones moderately 
robust, and opercular apparatus complete ; mandibular suspensorium 
nearly vertical or inclined backwards, and gape of mouth wide; 
ethmoid fused with vomers and forming a prominent rostrum; pre¬ 
maxillae not in contact mesially ; teeth pointed and conical, usually 
large on part at least of, all the dentigerous bones. Notochord 
persistent, sometimes with feeble ossifications in the sheath; verte¬ 
bral arches very numerous and closely arranged. Fin-ravs slender 
and closely set, articulated and divided distally; fulcra minute or 
absent. Dorsal fin short and acuminate. Scales thin and rhombic, 
sometimes with rounded postero-inferior angle. 
«*• 
Synopsis of Genera. 
I. Trunk elongate, fusiform. 
No ossifications in notochordal sheath ; fin- 
fulcra absent; pelvic fins present; 
dorsal fin opposed to much-extended 
anal fin .. . 
Ditto, but anal fin not much extended.... 
Ossified pleurocentra and hypocentra ; fin- 
fulcra minute; pelvic fins present; 
dorsal fin opposed to much-extended 
anal fin. 
Ossifications in notochordal sheath absent 
or rudimentary ; fin-fulcra absent; 
pelvic fins absent; dorsal in advance 
of anal fin .. . 
II. Trunk robust and fusiform. 
Ossifications in notochordal sheath absent 
or rudimentary ; principal teeth round 
in section; pelvic fins absent; dorsal 
in advance of anal fin, which is not 
much extended. 
No ossifications in notochordal sheath ; 
principal teeth round in section ; ros¬ 
trum never much produced; pelvic 
fins small; dorsal fin arising in ad¬ 
vance of much-extended anal fin ... . 
Apparently as Hypsocormus, but principal 
teeth laterally compressed, with sharp 
edges, in complete sockets, and rostrum 
often much produced . 
Sciuropsis (p. 375). 
Prosauropsis (p. 376). 
Euthynoms (p. 377). 
Asthenocormus (p. 380). 
Pachycormus (p. 380). 
Hypsocormus (p. 390). 
Protospliyrcena (p. 399). 
