CYPEJNID^E. CVIII. 283 



"masticatory" surface is an excavated space usually at the base 

 of the hook. Sometime when no masticatory surface is present a 

 lateral bevel of the edge of the tooth much resembles such a sur- 

 face, and should be carefully examined. In young individuals of 

 many species the 'edges of the teeth are more or less crenate or 

 serrate. This condition is permanent in the Southwestern genus 

 Cypnnella and in Notemigonus. 

 * Native species; fins without serrated spines; dorsal fin short, 



of less than 10 rays, 

 f Dentary bones slender, arched and widely separated except at 



their symphysis ; lower jaw not three-lobed. 

 \ Air-bladder suspended in the abdominal cavity and sur- 

 rounded by many convolutions of the long alimentary 

 canal, which is six to nine times the length of the body ; 

 (Campostomatince.) 



Teeth in Ihe principal row 4 4, with oblique grinding 

 surface and no hook ; mouth inferior ; lips sheathed, 

 the upper pr6tractile ; sexual differences very great, the 

 males covered with large tubercles in spring. 



CAMPOSTOMA, 1. 

 \\ Air-bladder above the alimentary canal and contiguous to 



the roof of the abdominal cavity. 



b. Rudimentary dorsal ray forming a sort of spine separated 

 from first developed ray by a membrane ; head short ; 

 mouth small, inferior; upper jaw protractile; teeth 4 

 4, with grinding surface, not strongly hooked ; aliment- 

 ary canal elongate, two or three times length of body ; 

 males with very large tubercles on the snout; (fins 

 short; a black spot on front of dorsal about halfway 

 up ; scales in front of dorsal small.) 



c. Lateral line incomplete ; body short ; head round. 



PIMEPHALES, 2. 

 cc. Lateral line complete ; body rather elongate. 



HYBORHTNCHUS, 3. 



66. Rudimentary ray at beginning of dorsal, not spine-like, 

 firmly attached to the first developed ray. 



d. No barbel at the angle of the mouth. 



e. Teeth 4 4, cultriform, without hook, and with oblique 



