35. HYODONTIDiE — HYODON. 
259 
Family XXXV.— HYODONTIDJ^. 
{The Moon Eyes ) 
Body oblong, compressed, covered with moderate-sized, brilliantly 
silvery, cycloid scales. Head naked, short, the snout blunt. Mouth 
moderate, oblique, terminal, the jaws about equal. Premaxillaries not 
protractile. Maxillary small, slender, without evident supplemental 
bone, articulated to the end of the premaxillary, and forming the lat- 
eral margin of the npjier jaw. Dentition very complete. Premax- 
illary and dentary bones with small, Avide-set, cardiform teeth. Max- 
illaries with feeble teeth. A row of strong teeth around the margin 
of the tongue, the anterior canine and very strong ; between these is a 
band of short, close-set teeth. Vomei- with a long, double series of close- 
set, small teeth. Similar series on the palatines, s^ihenoid, and ptery- 
goids. Sides of lower jaw fitting within the upper, so that the denta- 
ries shut against the palatines. Eye very large, the adipose eyelid not 
much developed. Preorbitals very narrow, i^^ostrils large, those of 
each side close together, separated by a flap. Gill-membranes not con- 
nected, free from the isthmus, a fold of skin covering their base. No 
guhir lilate. Branchiostegals 8-10. Gill-rakers few, short and thick. 
Psendobrauchi® obsolete. Lateral line distinct, straight. Belly not 
serrated. Dorsal fin rather posterior. Anal elongate, low. Ventrals 
well developed. Caudal strongly forked. No adipose fin.. Stomach 
horseshoe-shaped, without blind sac; one pyloric ccecum. Air-bladder 
large. No oviducts, the eggs falling into the cavity of the abdomen 
before exclusion. A single genus, with 3 known species, inhabiting 
the fresh waters of North America. 
{Hyodontidce Gunther, vii, 375, 376.) 
1 a ’7.— HYODOrV Lo Sueur. 
2[oon Eyes. 
{Hiodon 'Le Sueur, Jouru. Acad. Nat. Sci. Phila. i, 334, 1818: type Hiodon tcrgisus Le 
Sueur. ) 
Generic characters included above, {voscdrji;, hyoid; ddtu:/, tooth; 
“hyoid” is the bone shaped like the letter P, forming the base of the 
tongue.) 
* Belly in front of ventrals strongly carinated ; dorsal rays (developed) 9. 
432. H. alosoides (Raf.) J. & G. 
Body closely comiiressed, becoming deep in the adult. Eye mod- 
erate, smaller than in other species, about 3^ in head, the maxillary 
