CYPKINID.^. — XXVI. 57 



Silvery, sides with some black specks. Illinois R. (Prooably not 

 a Not r op is.) 



cc. Teeth 1, 4-4, 0; 1, 4-4, 1; or 1, 4-4, 2; the grinding surface more or 

 less developed. 

 h. Head comparatively large, 3| to about 4 in length ; teeth 1, 4-4, 1 ; 

 species of small size. (Alburrwps Girard.) 

 i. Eye moderate, 4 in head in adult. 



lOG. N. gilberti Jordan & Meek. Slender, with long tail; head 

 long, liattish above ; snout moderate ; mouth rather large, little 

 obliciue, the lower jaw included. Scales before D. 17; D. slightly 

 behind V. Greenish, sides with dusky streak and dark specks. 

 Head 4 ; depth 5. A. 9. Scales 5-35-4. L. 2^. Iowa and Mo. 

 (To Prof. Charles Henry Gilbert.) 



a. Eye very large, 2^ to 3 in head. 



107. N. boops Gilbert. Body compressed, the back elevated; 

 tail slender ; snout short, not blunt ; mouth terminal, very oblique, 

 lower jaw not included ; maxillary to front of eye ; D. over V. ; 

 12 scales before dorsal. HeadSf; depth 4i. A, 7. Scales 5-36-2. 

 Teeth 1, 4-4, 1, with deep, grinding surface, the inner edge strongly 

 crenate. L. 3. Olivaceous sides with dusky streak and dark specks. 

 S. Ind. to Iowa and Ark., common S. W. in cold streams, (^ovs, 

 bull ; w;//-, eye.) N. scabriceps Jordan & Gilbert, not of Cope.) 



hh. Head short, bluntish, about 5 in length in adult; species of large 

 size and silvery coloration. (Hudnonius Girard.) 



108. N. hudsonius (De Witt Clinton). Spawn -Eater. 

 " Smelt." Body elongate, moderately compressed ; head short, 

 with blunt snout ; eye very large, 3 to 3J- in head ; mouth small, 

 subinferior; lateral line slightly decurved ; 12 to 18 scales before 

 dorsal ; fins rather small. Pale olive, young always with a round 

 black spot at base of caudal ; sometimes a dark lateral band ; fins un- 

 marked. Head 4^ to 5 ; depth 4^ to 5. D. 8. A. 8. Scales 5-39-4. 

 Teeth variable, sometimes 2 in one of lesser rows, sometimes none 

 of them with grinding surface. L. 10. Lake Superior to N.Y., 

 and S. in coastwise streams to Ga., abundant and very variable. N. 

 specimens usually have teeth 2, 4-4, 1. Southern examples, Va. 

 to Ga. (var. amarus Girard), usually have teeth 1, 4-4, 1 or 0. 

 The species seldom ascends small streams. (From Hudson R.) 



bb. Scales very closely imbricated along sides of body, most of them deeper 

 than long ; body usually compressed. 

 j. Pharyngeal teeth usuall}' 4-4, tiieir edges serrate. {Moniana Girard.) 



109. N. lutrensis (Baird & Girard). Adult with the body 

 deep, strongly compressed, the back arched; young variously elon- 

 gate or elliptical ; head short, blunt ; mouth moderate, oblique, the 

 lower jaw included ; eye small, about 4 in head ; lateral line strongly 



