ADDENDUM. 
103 
From an examination of vomers of many specimens of Arctic and New England charrs 
of the S. alpinus group as well as of S. fontinalis and S. namaycush, the author of the present 
Memoir concluded, as has already been seen, that the S. alpinus group rather than S. fontina- 
lis is intermediate. However, re-examination of the same vomers and Regan’s statement and 
diagrams suggest that neither the S. alpinus group nor the S. fontinalis group is intermediate, 
but that both vary considerably and each intergrades independently with N. namaycush. 
This conclusion is in conformity with the suggestion previously expressed in the present 
Memoir regarding the origin of the charrs, to the effect that S. namaycush is an older derivative 
of a common parent stock and that the S. alpinus group and S. fontinalis are later divergents. 
