494 filhertes of the united states. [1^8] 



TRYGONIDiE. 



Genus TRYGON Adanson. 



1 70. Tryg'ou saMiia Le Sueur. Sttngaree ; Sting-ray. 

 Florida. 



This species is not uncommon in Lake Monroe, where 

 Professor Baird found it April 2, 1877. 

 22818. Pensacola, Florida, 1878, Silas Stearns. 



PETROMYZONTIDiE. 



Genus ENTOSPHENTJS Gill. 



171. Eiitosphenus ttfidentatus (Gairdner) Gill. Three- 

 toothed Lamprey. 



Coast of California and northward, ascending streams. 

 The example shown is referred to in a paper by Bean, 

 Proc. U. S. Nat. Mus., v, p. 93, June 12, 1882. 



30295. Fort Walla Walla, Washington Territory. May 6, 1881. Capt. 

 Ckas. Bendire, IT. S. A. 



Genus AMMOCCETES Dumeril. 



173. Ammocflefes niger (Raf.) Jordan. Small Black Lam- 

 prey. 

 Great Lakes ; Ohio Valley ; Upper Mississippi Valley, 

 ascending streams to deposit its eggs ; abundant. 

 This is a small lamprey, seldom exceeding 10 inches in 

 length and supposed to be identical with the Euro- 

 pean A. brancMalis ; this, however, is a mere suspi- 

 cion and not based upon comparison of European 

 with American examples. 



12517. Waukegan^ Illinois. J. W. Milner. 



Genus PETEOMYZON Linne. 



173. Ichtliyomyzon argenteus (Kirtland) Girard. Silvery 

 Lamprey. 



Great Lakes; Mississippi Valley; ascending small 

 streams at the spawning season in spring. 



This species reaches a length of 12 inches ; it is prop- 

 erly a Petromyzon. In the specimens of this species 

 and J. castaneus Grd. in the National Museum the 

 difference in the number of mandibular teeth is con- 

 stant. 

 7419. Louisville, Kentucky. 



