KEY TO FAMILIES OF PISCES. 81 



J. Jaws attenuate, forming a long, snipe-like beak. 



NEMICIITHYID^E, 56. 

 JJ. Jaws not attenuate. 



K. Tail tapering into a filament SACCOPHARYNGII>J, 54. 



KK. Tail not filamentous. 



M. Maxillaries and premaxillaries distinct ZoARCnxas, 115. 



MM. Maxillaries and premaxillaries more or less coalescent 



with vomer and palatines. 



ANGUILLIDJE, 53. 

 GG. Body not eel-shaped. 



N. Breast with a sucking dislr. 



O. Skin smooth LIPARIDHXE, 109. 



OO. Skin tubercular C YCLOPTERHWE, 110. 



KN. Breast without sucking disk. 



P. Teeth in each jaw confluent into on&.,* 



Q. Body compressed, rough ORTH3CGOIU8CUXE, 131. 



QQ. Body not compressed, spinous-.DiODONTiD^E, 130. 

 PP. Teeth in each jaw confluent into two. 



TETRODONTID^E, 129. 

 PPP. Teeth separate. 



R. Body enveloped in a bony box. ..OsTRACinxE, 127. 



RR. Body not mailed STROMATEHXE, 77. 



CC. Gill membranes free from the isthmus. 



S. Vent at the throat. 

 T. Vertical fins confluent ; body eel-shaped. 



FlERASFERIDJE, 117. 



TT. Vertical fins separate ; body oblong. 



AMBLYOPSIIXE, 48. 

 SS. Vent posterior. 



U. Caudal fin wanting ; body naked. 



TRICHIURID.E, 73. 

 UU. Caudal fin present. 



V. Upper jaw prolonged into a sword. 



* XIPHIID^E, 72. 



VV. Upper jaw not prolonged into a sword. 

 W. Body ovate, much compressed. 



STROMATEID.E, 77. 

 WW. Body oblong or elongate. 

 X. Gill membranes broadly united; teeth 



present. 

 Y. Dorsal fin of spines only. 



BLENNIIIME, 112. 

 YY. Dorsal fin of soft rays only. 



COXGROGADIIWE, 116. 



YYY. Dorsal fins 2, anterior spinous, 



posterior soft COTTIDJE, 107. 



XX. Gill membranes separate. 



Z. Jaws toothless, the lower jaw 



projecting AMMODYTID^E, 69. 



ZZ. Jaws with teeth, lower not pro- 

 jecting OPHIDIID/E, 118. 



Bull. Nat, Mus. No. 16 -6 



