Occasional Papers of the Museum of Zoology 1 1 



6. Eniosphcnus tridcntatus ciliatus Ayres 

 Two names, Pctromyzon ciliatus Ayres-* and Pctromyzon 

 cpihexodon Gill-'' have been based on this southern form of 

 Entosphcnus tridcntatus, which is characterized by the reduced 

 number of segments. 



7. Entosphcnus japonicus Martens 

 The large lamprey of Japan is an Entosphcnus, as Regan-*^ 

 has shown. The species is of wnde distribution, occurring 

 also in the White Sea, as Regan suggested. We are now able 

 to state that the lamprey of the Yukon, described as Amnio- 

 coetes aureus by Bean,^" is also conspecific with japonicus. 



In our opinion, Lampetra mitsukurii major Hatta,-^ of 

 which we have examined topotypic material,-'' is based on 

 breeding individuals of Entosphcnus japonicus. The distinc- 

 tive features of this nominal form, as pointed out by the 

 describer, are just those which, as Gage^" has shown, distin- 

 guish breeding from non-breeding adults of Petromyzon mari- 

 nus; the bluntness of the teeth is due to wear. We find that 

 like changes take place in Entosphcnus tridcntatus and in Lam- 

 petra -flmnatilis (q. v.), 



8. Entosphcnus appendix DeKay 

 Petromyzon appendix DeKay^^ we regard as assuredly based 

 on the species currently knowai as Lampetra or Entosphcnus 



-* Proc. Cal. Acad. Nat. Sci., 1855, p. 44. 

 25 Proc. Acad. Nat. Sci. Phila., 1862, p. 331. 

 2«Ann. Mag. Nat. Hist., Ser. 8, Vol. 7, 191 1, p. 202. 

 2T Proc. U. S. Nat. Mus., 4, 1881, p. 159. 

 28Annot. Zool. Jap., 7, 191 1, p. 268, pi. 9. 



29 Recorded by Jordan and Snyder (Proc. U. S. Nat. Mus., 2^, 1901, 

 734), as Lampetra mitsukurii. 



30 Wilder Quarter-Century Book, 1893, p. 439, pi. 3. 



31 New York Fauna, Fishes, 1842, p. 381, pi. 64, fig. 211. 



