146 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
CC. Teeth 5-5 or 4-5; pseudohranchite present; dorsal fin inserted poste- 
riorly. 
D. Lateral line comiilete ; rudimentary caudal rays numerous; anal basis 
elongate.. L avinia, 74. 
DD. Lateral line incomijlete ; anal basis short ; scales minute. 
ClIROSOMUS, 75. 
CCC. Teeth 4-4 ; dorsal fin nearly median. 
E. First (rudimentary) ray of dorsal slender, firmly attached to the first 
developed ray. 
F. Scales very small, 85-90 in the lateral line, which is complete. 
ZOPHENDTJM, 76. 
FF. Scales larger, 35-60 in the lateral line. 
G. Lateral line complete H ybogxatiius, 77. 
GG. Lateral line incomplete Coliscus, 78. 
EE. First (rudimentary) ray of dorsal someAvhat enlarged and blunt, 
connected by mem- 
brane with the first de- 
A^eloped ray. 
H. Lateral line incomplete Pimkpiiales, 79. 
HH. Lateral line complete Hyborhyxchus, 80. 
U Intestinal canal short, less than twice the length of the body ; teeth hooked, the 
grinding surface, if pres- 
ent, narrow or rudimen- 
tary ; peritoneum usu- 
ally pale. 
$ Dentary bones parallel, united for their whole length. {Exo~ 
dJossina’.) 
I. Premaxillaries not protractile; mandible with a conspicu- 
ous fleshy lobe on each 
side at base. 
Exoglossum, 81. 
§5 Dentary bones arched, free from each other, except at 
the symphysis. {Lcu- 
ciscin a\) 
J. Abdomen behind ventral fin s not compressed to an edge, 
the scales passing over 
it ; anal basis generally 
short. 
K. Teeth in the main row 4-4. 
L. Maxillary without barbels. 
M. Jaws each with a hardened bony sheath; first 
ray of dorsal spine-like, 
eomiected by membrane 
with the first developed 
ray ; teeth 4-4. 
COCIILOGXATIIUS, 82. 
MM. Jaws without bony sheath. 
N. Lower jaw with the lip thin or obsolete, not 
developed as a fleshy 
lobe on each side at 
base. 
O. Mandible, iuteropercle, and suborbital not 
cavernous. 
P. Teeth 4-4, or 1, 4-4, 1 (1, 4-4, 2 in one spe- 
cies). 
