350 LAMPREYS. 



tinct in adult, concealed in young; mouth small, with 

 inconspicuous teeth; color ashy silvery, with numerous 

 small black dots; larger ones above the gill openings; 

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

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

 bott.) 



3. A. hirudo f (Grd.) Jor. LEECH LAMPEEY. Grayish, 

 unspotted; eyes small; "mandibulary plate with seven 

 teeth;" appearance of P. argenteus. Great Lakes and 

 Miss. Valley. 



