IS0SP0NJ3YLI. 
O 
Parietal bones partly meeting in the 
middle line ; opercular appara¬ 
tus incomplete, with few bran- 
chiostegal ravs: abdominal ver- 
O V 7 
tebrae with transverse processes. 
Maxilla and premaxilla firmly fixed; 
opercular apparatus complete, 
with few branchiostegal rays; 
abdominal vertebras without 
transverse processes . 
Maxilla loosely attached, with two 
supramaxillaries ; opercular 
apparatus complete, with few 
branchiostegal rays; abdominal 
vertebrae without transverse 
processes ; postclavicle over¬ 
lapped by clavicle ; pelvic fins 
enlarged and far forwards .... 
Maxilla loosely attached, usually 
with two supramaxillaries; 
opercular apparatus complete, 
with few branchiostegal rays; 
abdominal vertebrae with short 
transverse processes ; post- 
clavicle overlapping clavicle ; 
dorsal fin median, and no adi¬ 
pose dorsal . 
As Clupeidce, but with adipose dor¬ 
sal fin and postclavicle over¬ 
lapped by clavicle . 
II. Premaxilla partly or completely excluding 
maxilla from margin of upper jaw; 
no gular plate. Precoracoid arch re¬ 
duced or absent. 
(a) Parietal bones meeting in the middle 
line, and squamosal bones well 
developed. 
Maxilla partly entering gape ; oper¬ 
cular apparatus incomplete; 
scapular arch supported by post¬ 
temporal bone ; scales cycloid, 
regularly arranged; lateral line 
near ventral border of flank .. 
Premaxilla completely excluding 
maxilla from margin of upper 
jaw ; opercular apparatus com¬ 
plete ; scapular arch supported 
by rigament, without post- 
NotopteriS.® (p. 85). 
Chirocentrid^ (p. 86), 
Ctenothrissid.® 
[(p. 119). 
Clupeid^ (p. 1:18). 
Salmonid.® (p. 159). 
Halosaurid-® (p. 162). 
