ISOSPONDYLI. 
a 
Parietal bones partly meeting- in the 
middle line ; opercular appara- 
tus incomplete, with few brau- 
chiostegal rays ; abdominal ver- 
tebras with transverse processes. 
Maxilla and premaxilla iirmly fixed ; 
opercular apparatus complete, 
with few brauchiostegal rays ; 
abdominal vertebra? without 
transverse processes 
Maxilla loosely attached, with two 
supramaxillaries ; opercular 
apparatus complete, with few 
branchiosteg'al rays ; abdominal 
vertebrae without transverse 
processes ; postelavicle over- 
lapped by clavicle ; pelvic fins 
enlarged and far forwards .... 
Maxilla loosely attached, usually 
with two supramaxillaries ; 
opercular apparatus complete, 
with few brauchiostegal rays ; 
abdominal vertebra? with short 
transverse processes ; post- 
clavicle overlapping clavicle ; 
dorsal fin median, and no adi- 
pose dorsal 
As ClupeidiB, 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 gnlar plate. I’recoracoid 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 Hank . . 
Premaxilla completely excluding 
maxilla from margin of upper 
jaw ; opercular apparatus com- 
plete ; scapular arch supported 
by .igaiuent, without post- 
Notopterid.® (p. 85). 
Chirocentrid.® (p. 86), 
Ctenothrissid,® 
[(p. 119), 
Clupkid.® (p. 128 ). 
Salmonid,® (p. 159). 
HALOS AtTRIDJE (p. 162). 
