2 UniversUy of Michigan 



This report is only a systematic outline of the northern 

 lampreys. We hope to obtain much additional material, and 

 if possible to find characters by which ammocoete material 

 can be more certainly identified. Until such additional infor- 

 mation is at hand, we consider it premature to enter into a 

 discussion of the geographical distribution and evolution of 

 the North American lampreys. The ranges of the various 

 forms, as given in the following key, are completely verified 

 by material examined. 



In the classification of the lampreys a comparison of denti- 

 tion is indispensable. In order to render them clearer, the 

 descriptions of the teeth in the following key should be sup- 

 plemented by figures, to which we here append references in 

 the following list. 



List of the Holarctic Lampreys, with References to 

 Figures of Dentition 



Genus Ichthyomyzon Girard. 



Subgenus Ichthyomyzon Girard. 



IchthyoDiyzon concolor Kirtland : Bensley, Contr. Can. Biol., 



1911-1914 (1915), pl- I, fig- 5- 

 Subgenus Reighurdina (new). 



Ichthyomyzon unicolor DeKay : Reighard and Cummins, Occ. 



Pap. Mus. Zool., Univ. Mich., No. 31, 1916, pl. 2, fig. i. 



Genus Petromyzon Linnaeus. 



Subgenus Petromyzon Linnaeus. 



Petromyzon marinus Linnaeus : Gage, The Wilder Quarter- 

 Century Book, 1893, pl. 6, figs. 19, 20; Smitt, Hist. Scand. 

 Fishes, pt. 2, 1895, p. 1184, fig. 352; Bade, Die mitteleuro- 

 paischen Siisswasserfische, 2, 1902, p. iii, fig. 85; Fowler, 

 Proc. Acad. Nat. Sci. Phila., 1907, p. 462, fig. i. 



Subgenus Caspiomyzon Berg. 



Petromyzon wagneri Kessler, "Trud. St. Petersb. Obshch. 

 Estestv., I, 1870, pp. 270, 302, pl. 3, figs. 4, 5." 



Subgenus Eudontomyzon Regan. 



Petromyzon danfordi Regan: Wajgel, Verh. zool.-bot. Ges. 

 Wien, 33, 1883 (1884), pl. 17, fig. 3 (as Petromyzon planeri; 

 details inaccurate). 



