14G CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



' CC. Tot-Hi .">-."> or 4-5; pseudobranchiai present; dorsal fin inserted poste- 

 riorly. 



D. Lateral line complete; rudimentary caudal rays numerous; anal basis 



elongate.. LAVIXIA, 74. 

 DD. Lateral line incomplete ; anal basis short ; scales ininutt-. 



CllltoSoMfS, 75. 



CCC. Teeth 4-4 ; dorsal fin nearly median. 



E. First (rudimentary) ray of dorsal slender, firmly attached to the first 



developed ray. 

 F. Scales very small, 85-90 in the lateral line, which is complete. 



ZOPIIEXDUM, 70. 

 FF. Scales larger, 35-GO in the lateral line. 



G. Lateral line complete HYBOGXATIIUS, 77. 



GG. Lateral line incomplete COLISCUS, 78. 



EE. First (rudimentary) ray of dorsal somewhat enlarged and blunt, 



connected by mem- 

 brane with the first de- 

 veloped ray. 



H. Lateral lino incomplete PIMEPIIALES, 79. 



HH. Lateral line complete HYBOIUIYXCIIUS, 80. 



it Intestinal canal shortness than twice the length of the body ; teeth hooked, the 



grinding surface, il'pre>- 

 eur, narrow or rudimen- 

 tary; peritoneum usu- 

 ally pale. 

 $ Dentary bones parallel, united for their whole length. (Exo- 



f/lossina:) 



I. Premaxillaries not protractile; mandible with a conspicu- 

 ous llt-.shy lobe on e;uh 

 side at base. 



EXOGLOSSUM, 81. 



$$ Dentary bones arched, free from each other, except at 



Hie symphysis. (/,<- 

 ciscinffi. ) 

 J. Abdomen behind ventral fins not compressed loan edge, 



tin- BOaleS pas>ing over 



it; anal basis generally 

 short. 



K. Teeth in the main row 4-4. 

 L. Maxillary without barbels. 



M. Jaws each with a hardened bony sheath; first 



ray of dorsal spine-like, 

 connected by membrane 



Willl tile lirst developed 



ray : leel h 1-1. 



CociiLocx.vnrus, 82. 

 MM. Jaws without bony sheath. 

 N. Lower jaw with the lip thin or obsolete, not 



developed as a fleshy 

 lobe on each side at 

 base. 

 O. Mandible, inten.perele, and snborbital not 



cavernous. 



P. Teeth 4-4, or 1, 4-4, 1 (1, 4-4, 2 in one spe- 

 cies). 



