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. wpyptera, Ab 

 bott.) 



2. /. castaneus, Grd. Chestnut-colored without spots; 

 eyes inconspicuous; &quot; mandibulary plate with nine teeth.&quot; 

 Minn. 



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

 &quot; mandibulary plate with seven teeth.&quot; Ark. 



