316 LAMPREYS. 



small black dots; larger ones above the gill openings; 

 L. 12. Great Lakes and Ohio Valley, E. to N. Y., fre- 

 quent. (Ammoccetes concolor, Kirt., A. cepyptera, Ab- 

 bott.) 



2. /. casta neus, Grd. Chestnut-colored without spots; 

 eyes inconspicuous; " mandibulary plate with nine teeth." 

 Minn. 



3. /. hirudo, Grd. Grayish, unspotted; eyes small; 

 "mandibulary plate with seven teeth." Ark. 



