444 



THE AMERICAN NATURALIST 



[Vol. XLI 



same. With the possibilities arising from more extended com- 

 parison of material representing a wider range of variations, the 

 conviction l)ecomes stronger that the opinion so stated is a tenable 



Acer torontoniensis n. sp.— The Don collection embraces a 

 number of specimens, some of them fairly perfect, representing 

 a species of maple altogether iniknown, either in the fossil or the 

 living state. This leaf appears to present two principal variations 

 which depend in part upon the relative depths of the principal 

 sinuses and the character of the minor lobes or teeth, but chiefly 

 upon the fact that in one form the base of tlie leaf is only slightly 

 if atalllobed. while in the (.1 her case two large lobes extend down- 

 ward from tiic iii-criii)ii of ilic blade mi the petiole and enclose 

 the latter. 'i\v() i)rin( ij)al veins extend from the base of the mid- 

 rib to the corresponding principallobe.>, and two subordhiate veins 

 of varving prominence extend diagonally downward from near 

 the same point, into the two minor and variable lobes which form 

 the base of the leaf blade. From this description, as also from 

 the two specimens shown in Fig. 2 it will be seen that this leaf 

 belongs to the same group with our common hard maples. Com- 

 parison with these latter also shows that its nearest representative 

 among existing species is the common rock or sugar maple, Acer 

 .s«rr/mrm?m Wang. Comparing the upper fossil of Fig. 2 with 

 one of the more ordinary types of leaf of the sugar maple, it ai)j)ears 

 that the chief points of difference are to be found in the form of 

 the sinuses and in the character of the large teeth or smaller lobes. 

 If again we compare the lower fossil leaf in Fig. 2 with the cor- 

 responding type of leaf of the sugar maple, the resemblance be- 

 <-omes nnK-h' stronger bv reason of the similar basal lobes, which 

 ]ri\e unfortunatelv been much broken away in the fossil. The 

 dillVrences noted are such as might well result from changes inci- 

 <lent to natural development, whereby the more simple tends in 

 the direction of the more compound, and ul.en to this there are 

 joined the actual resemblances, the\ >uu-e>i a \ er> nitmiate rela- 

 tion between the existing sugar maple and the t'o-sil, of such a 

 1 ... <l,.,t tl..- jailer ina\ i)e tlie ancestral form 



