Occasional Papers of the Museum of Zoology 9 



omyson sp.'' by Hankinson/^ and we have found it common 

 throughout Michigan. An ammocoete from the St. Lawrence 

 drainage at Madrid, New York, seems to belong to the same 

 species. 



Although not absolutely certain, it is highly probable that 

 the specimens named Anmiocoetes unicolor by DeKay,^- from 

 a tributary to Lake Champlain, and Anmiocoetes borealis by 

 Agassiz,^" from a stream flowing into Lake Superior, were 

 larvae of this species. It is certain that both names were 

 based on a species of Ichthyomyzon, and the large size and 

 the shape of the types suggest that they belonged to this spe- 

 cies rather than to concolor. 



3. Petromyson marinus Linnaeus 



We concur in the prevalent view that Petromyzon ameri- 

 canus Le Sueur^* is identical with P. marinus of Europe. 

 Petromyzon nigricans DeKay^^ merely represents the uniformly 

 colored young, Ammocoetes bicolor DeKay^^ the larva, of the 

 sea lamprey. The dwarfed race {P. marinus dorsatus Wil- 

 der),^' land-locked in the New York lakes, of which we have 

 examined material, does not appear to use worthy of even 

 subspecific recognition.^* Bathymyzon bairdii Gill^^ and 

 Oceanomyzon wilsoni Fowler-" we hold to be strict synonyms 

 of P. marinus, each having been based on marine specimens 



1^ Occ. Pap. Mus. Zool., Univ. Mich., No. 89, 1920, p. 5. 

 1- New York Fauna, Fishes, 1842, p. 383, pi. 79, fig. 250. 

 1^ Lake Superior, 1850, p. 252. 

 1^ Trans. Am. Phil. Soc, i, 1818, p. 383. 



15 New York Fauna, Fishes, 1842, p. 381, pi. 79, fig. 247. 



16 Ihid., p. 383, pi. 79, fig. 248. 



" In Jordan and Gilbert, Bull. U. S. Nat. Mus., 16, 1883, p. 



18 See also Meek, Ann. N. Y. Acad. Sci., 3, 1886, pp. 285-289. 



19 Proc. U. S. Nat. Mus., 5, 1883, p. 254. 



20 Proc. Acad. Nat. Sci. Phila., 59, 1907 (1908), p. 462, 



