sclenid.® of the eastern united states coast. 
147 
In using the key proper, the letters with their corresponding notes should be 
read off until a letter is found whose note disagrees with the specimen in hand. 
Then all intervening matter should be passed over until the last letter’s double 
is reached. 
Table 2 (p. 149), which gives the number of rays of the dorsal and anal fins of 
each species treated in this paper, is intended to be used in connection with the 
key. In identifying a specimen by means of this table it is simply necessary to 
count the rays (not the spines) of the dorsal and anal fins. Reference to the table 
TOTAL LENGTH * 
VENTRAL nn 
LINING rf GILL CAVITY 
ARCH 
GILL RAKERS 'GILLS 
Fig. 1. — Diagram of a sciasnid explaining terms used in key. 
isolates the specimen in hand, or at least brings it down to a few possibilities from 
which the specific appelation should be determined readily by reference to the key. 
GLOSSARY OF TERMS USED IN KEY. 
Canine teeth . — Conical teeth in jaws, larger and longer than the rest. 
Cavernous . — Containing cavities, empty or filled with mucus. 
Ctenoid scales . — Scales with rough edges, due to minute prickles being directed backward. Can be 
distinguished from smooth scales (cycloid) by passing finger along side of fish from tail to head. 
Deciduous teeth . — Such that readily fall out on slight pressure. 
Excluded jaw . — Projecting beyond. Said of lower jaw when it reaches farther forward than upper, as 
opposed to “included,” in which case the opposite is true. 
38122°— 23 2 
