LAMPREYS AND F[SHES OF INDIANA. 273 



c. Cheeks and opercles almost wholly naked. 



Scales along the lateral line about seventy- 

 seven, macrocephalum, p. 274. 

 Scales along the lateral line about fifty-five. 



ouachiUe, p. 274. 

 cc. Cheeks and opercles scaled. 



Scales of lateral line fifty-five ; dorsal rays 



XII, 13. ouachitce, p. 274. 



Scales of lateral line sixty-five to seventy-five ; 



dorsal XIII to XV, 12. mjyro, p. 274. 



Scales of lateral line sixty-eight ; dorsal XII, 



13. phoxocephalum, p. 275. 



bb. Gill-membranes broadly united across the isthmus ; 



dorsal rays XIII, 14. scierum, p. 276. 



aa. Palatine teeth not present. Dorsal rays XI, 11. 



evides, p. 276. 

 2. Mid-ventral line covered with scales of the common sort. 

 a. Anal fin with rays II, 9 to 11. 



Scales 11-75-16; dorsal XI or XII, 13. 



nianguce, p. 277. 



Scales 9-58-10; dorsal XII 12. viaculatum, p. 277. 



Scales 8-51-9 ; dorsal XIII, 13. variatuvi, p. 278. 



Scales 6-47-7; dorsal XII, 12. jessue, p. 282. 



aa. Anal with rays II, 7 or 8. 



Gill-membranes broadly united across the isthmus. 



zonale, p. 278. 

 Gill-membranes scarcely united. camnrum, p. 279. 



AA. Lateral line incomplete or wholly wanting. 



1. Lateral line developed on anterior part of body ; scales of the 

 lateral line forty or more, 

 a. Gill-membranes broadly united across isthmus. 



Head wholly without scales. flabellare, p. 280. 



Cheeks and opercles scaled. squarniceps, p. 280. 



aa. Gill-membranes little united, 

 c. Cheeks naked, or nearly so. 



Scales 11-74-16; dorsal XI or XII, 13 or 14; 

 anal II, 11 or 12. nianguce, p. 277. 



Scales 5-45-8; dorsal X, 12; anal II, 7. 



cccruleum, p. 28 L. 

 Scales 5-5C-8 ; dorsal XII, 12 ; anal II, 7. 



, tippecmioe, p. 282. 



cc. Cheeks scaled. 



Dorsals XII, 12; anal II, 9. jessice, p. 282., 



Dorsal IX or X ; anal II, 7. fusiforme, p. 282.. 



1 8 — Geology. 



