of the value of all the existing indications; especially as there is another 

 weak point always to be calculated with, viz., the imperfect exploration 

 of most parts. In the hope of inducing some competent botanist to make 

 a revision of the american collections, which may supply some future 

 worker on the N. W. Greenland flora with material less studded with "?", 

 I will point out where those collections seem to be kept. 



The specimens of KANE, HAYES, BESSELS, BURK and MEEHAN are 

 probably all included in the collections of the Academy of Natural Sci- 

 ences of Philadelphia; at least it is especially mentioned, that some of 

 them belong to that herbarium. The collections of WETHERILL were 

 determined at Harvard University, which probably possesses them. As 

 to where the "private collection" of GREELY is kept, I am entirely ignor- 



