24 
number of alder leaves found. In my opinion Ileer lias referred the leaves 
of A. gracilis to A. Kefersteinii, which would account for the fact that he 
has found no leaves which lie could assign to the fruiting cones of the A. 
gracilis. The only leaf (Plate XIX, fig. 14, of the work quoted), which lie 
designates as A. gracilis , is not an alder leaf, inasmuch as it shows plainly 
looped and more approximate secondary veins, which do not occur in A Inns. 
On the other hand, at least the leaves figured under Pigs. 3 and 4 in the same 
work belong to that species, as I found from the fruiting branch of the A. 
gracilis from Leoben, in connection with which there is a leaf almost per- 
fectly identical with the leaf numbered 3 just referred to. It is probable 
that Pig. 8, as well as the leaves of Alnus Kefersteinii parvifolia, Heer, in 
general should also be referred to this species. 
I certainly agree with Ileer in his opinion that the alders which occur 
in the Possil Plora of Kumi are only forms of A. Kefersteinii and A. gracilis. 
I have before me well-preserved leaves of both from the strata of Kumi. 
Amongst these the leaves of A. Kefersteinii appear to be much more rare, 
and, in his “Possilen Plora von Kumi,” Unger has figured one of them, an 
imperfectly preserved leaf fossil, whose margin is wanting, as A. sporadum. 
All the leaves designated by him as A. cycladum, however, belong to A. 
gracilis, and not to A. Kefersteinii, as supposed by Ileer. 
I have yet to consider the occurrence of A. gracilis in the Tertiary 
Plora of Iceland, not only as regards the fruit, but also as regards leaves. 
The fruiting cones, PI. XXV, figs. 4b, 5, 0, 7, in O. Ileer’s Plora Possilis 
Arctica, Part I, are erroneously designated as A. Kefersteinii ; their corres- 
pondence with those of A. gracilis is so apparent that they must undoubtedly 
belong to the latter species. Of the few and generally very imperfectly pre- 
served alder leaves which have been found in the tertiary strata of Iceland, 
the fragment of a leaf, PI. XXV, fig. 19, in the work above quoted, corresponds 
both as regards dentation and venation to the one designated and figured as 
A. Kefersteinii parvifolia, in PI. XIX, fig. 2, in the “Miocene Plora of the 
Baltic.” As the latter, however, as already observed, is referable to A. 
gracilis , we must refer this one also to the same species, on account of the 
leaf fragment, Pig. 19, which fossil cannot possibly belong to JBetula macro- 
phylla, to which Ileer has referred it. That a birch fruit is occasionally found 
in the same piece of rock, together with the fragment of leaf referred to, 
cannot deprive the above argument of its force. Besides this, the birch fruit 
agrees very well with the leaf fragment, Pig. 18, whose well-preserved dentate 
