8 BERRY— A POSSIBLE EXPLANATION 



less objects described as fungi; there are 20 ferns; 28 conifers; 21 

 monocotyledons, of which most are fragments of grass- or sedge-like 

 leaves, generically and specifically undeterminable. Among the mono- 

 cotyledons are two nominal species of Flahellaria — a form-genus pro- 

 posed for undeterminable palm fossils. Neither of these is very con- 

 vincing, and if they are correctly figured by Heer I would never think 

 of calling them palms, and yet every textbook speaks of the Tertiary 

 palms of Greenland, although they always have been purely subjective. 



The bulk of the Greenland Eocene flora consists of dicotyledonous 

 leaves. Among these we find Ficus, but this does not mean that figs 

 were members of this flora. The determination of Ficus on Heer's 

 part was only tentative, and he published it with a question mark 

 behind it; moreover, it does not suggest any of the numerous species 

 of Ficus, either fossil or recent, with which I am familiar. Among 

 the Greenland Tertiary dicotyledons the following genera predomi- 

 nate: Populus, Salix, Alnus, Betula, Corylus, Fagiis, Quercus, Jug- 

 lans, Acer, Laurus, Andromeda, Fraxinus, Viburnum, Cornus, Mag- 

 nolia, Ilex, Celastrus, Rhamnus, Rhus, and Cratcegus. 



These are all genera that range for greater or less distances into, 

 and some, such as Populus, Salix, Alnus, and Betula, range entirely 

 across the cool-Temperate Zone. Any one is, of course, at liberty to 

 call this Greenland Tertiary flora " tropical " — after the most detailed 

 comparison and discussion its original describer did not so consider it, 

 nor do I. 



In nearly every case where a Greenland Eocene genus is indicative 

 of conditions warmer than cool-Temperate, as, for example, the gen- 

 era Pterospermites, Sapindus, Zisyphus, Colutea, Laurus, and Dal- 

 hergia, the botanical determinations can, and are, seriously questioned, 

 and all that they can be asserted to mean is that the respective forms 

 are similar to forms from other regions which some one, generally 

 Heer himself, called Colutea, Dalbergia, etc. 



The most northerly known Eocene flora is that described by Heer 

 in the fifth volume of his " Flora Fossilis Arctica " from near Cape 

 Murchison in Grinnell Land. As elaborated by Heer this flora com- 

 prised 30 species, but it may well be pointed out that a number of 

 these have no existence outside the literature of paleobotany. Thus 



