THIRTEENTH ANNUAL MEETING. 33 
to verify this statement. In the northern regions of America, 
also, they constitute one of the chief sources of food supply. 
These fishes possess many natural advantages over other inhabi- 
tants of the waters—they do not prey upon one another and 
their movements are not checked by dams and similar obstruc- 
tions. They yield vast numbers of eggs, which are readily de- 
veloped artificially, and it has recently been demonstrated that 
the young fry can be reared in confinement. All of the species 
but two have excellent food qualities and they exist in great 
abundance. We may well protect and cultivate these fishes 
whose importance and possibilities can scarcely be overesti- 
mated. - 
NortH AMERICAN SPECIES OF COREGONUS. 
A. Lower jaw included; gill-rakers about thirty or fewer, moderately 
long, or short and thick. 
a. Gill-rakers moderately long; maxilla } head, or more. 
7. Voneue with teeth; oill-rakers 23%) 5)... labradoricus. 
66. Tongue toothless, or nearly so. 
c. Nape arched and thick; gill-rakers 26-29. clupezformzs. 
cc. Nape arched and much compressed; gill-rakers 26 . . . xe/- 
SONZ. 
aa, Gill-rakers short; maxilla 4} head (4 in w¢l/¢amsonzz.) 
@. Mouth inferior. 
e. Body elongate; maxilla about 4 head; gill-rakers 17 . 
guadrilateralis. 
ee. Body oblong; maxilla about } head; gill-rakers 23... we/- 
lzamsontz. 
dd. Mouth not inferior; jaws nearly equal; maxilla about 4 
head; gill-rakers 22 . . kennzcottzz. 
AA. Lower jaw projecting, or jaws subequal; gill-rakers more than 30, 
long and slender. 
f. Body deep; scales little convex behind; gill-rakers 48.....- 
tulltbee. 
ff. Body oblong or elongate; scales strongly convex behind. 
g. Eye moderate (4 to + length of head). 
h. Dorsal base longer than post-orbital part of head; gill- 
PACES AOR ee ers ks lauretta. 
hh. Dorsal base shorter than post-orbital part of head. 
z. Teeth on premaxillaries and tongue; gill-rakers 39-44 .. . . 
NLeVLPUNNtS. 
