288 Mr. MuucHisoN on a Fossil Fox found at Q^nbigen near Constance, 



tinguisliable in the leaf, from the Acer villosum, a species of maple brought 

 from Nepaul by Dr. Wallicli. 



The specimens which I collected have been referred to Mr. Lindley, who 

 has favoured me with the following- report. "I have again examined your 

 (Eningen fossil vegetables^ but with as little success as before. That some 

 of the leaves may have belonged to plants still existing is highly probable; 

 but the evidence about many of them is not perfect enough to enable a 

 botanist to speak positively. I retain the opinion which I expressed to you 

 last year^ that one of them is the lateral pinna of Fraxinus rotundifolia ; and 

 I see no reason to change my belief that the lobed ones have belonged to 

 some kind or kinds of Acer. If they all belonged to one kind, it must have 

 been a species more variable in the foliage than any at present existing; but 

 it is possible that two kinds may have been intermixed. Some of the impres- 

 sions, particularly a beautifully perfect one, are not to be distinguished by 

 comparison from the young leaves of Acer opidifolunn, a species still existing 

 in Dauphiny and Piedmont; others are extremely like Acer pseudo-platanus 

 (the common Sycamore), but I cannot assert that they are the same; indeed 

 I incline more to consider them dilTerent. The fact is, that these forest trees 

 vary so much in the outline of their leaves, that it frequently is difficult to 

 determine them even from fresh specimens. 



" Among tlie fossils is however one in so good a state of preservation, that I 

 am able to say with confidence that it is not of any species at present native of 

 Europe, and I think unknown elsewhere. It is a large cordate roundish leaf with 

 the remains of a petiole, a coarsely toothed margin, and a distinct impression 

 of two elevated glands, at the point where the leaf joins the petiole. Now 

 there are no European trees in which these glands exist, that need be com- 

 pared with the fossil, except the poplar tribe ; and there is no known poplar 

 which bears leaves that do not essentially differ in character from this : I have 

 therefore named it Populus cordfolia. Populiis nigra, and all its varieties, 

 have smaller leaves, which are truncate, never deeply cordate at the base, and 

 their glands are both smaller and differently formed, Populus catiescens, in 

 which the leaves are cordate in an equal degree, and as large, has no glands, 

 and its outline is more ovate. Populus grccca has leaves with two glands 

 placed as in the fossil, but the leaves are much less cordate, and without 

 toothing at the margin. 



" Upon the whole I should say the fossils may be considered to consist of 

 one or two species of Acer, possibly referable to existing European species, 

 but probably extinct;— A plant tliat is not distinguishable from Fraxinus ro- 

 tund i/bli a ; — An extinct species of Poplar; and some other plants bearing a 



