lesqueeeux.] REVIEW OF CRETACEOUS FLORA. 323 



group. In the Kansas specimens only the epidermis of the leaf is 

 destroyed at a few places where the veinlets become perceptible. Gen- 

 erally, however, as in the specimens of Greenland, the primary veins 

 only can be seen. 



Of the fragments doubtfully referred to Flabellaria f and described 

 as F. minima, Cret. FL, p. 56, PI. XXX, fig. 19, nothing more has been 

 discovered in regard to their relation, which has to be considered as 

 unknown as yet. The same may be said of the peculiar vegetable form 

 described in Cret. FL, PL 1, fig. 6, as Pterophyllumf Haydenii, which 

 was supposed to represent some kind of Cicadece. It differs from any 

 species known of this family by the broad stem and short leaves, nar- 

 rowed to the point of attachment, and from these characters Professor 

 Heer thinks it referable to Conifers. 



Now, counting the leaf described as Dioscorea? cretacea, whose generic 

 reference may be doubted, but which evidently represent a species of 

 the Dioscorece or a monocotyledonous, and also the fragments referable to 

 Conifers in the description, we have to this time, in the flora of the Da- 

 kota group, and exclusively of the dicotyledonous, sixteen specific forms, 

 representing the cryptogamous acrogens by five Ferns, the phcenogamous 

 gymuosperms by nine Conifers, and the monocotyledonous by one glu- 

 maceous and one petaloid species. 



The first dicotyledonous leaves described in the Cretaceous Flora, 

 under the name of Liquidambar integrifolium, have been considered by 

 some authors as uucertain in regard to their generic relation merely on 

 account of their entire borders. The form of the leaves, however, espe- 

 cially as figured (PI. II), with the lobes slightly enlarged above the 

 sinuses, and then gradually narrowed to a slightly obtuse point, and 

 the nervation also, have the same character as those of the living Liqui- 

 dambar styraciflua. It is true that the four species of this genus known 

 in the present flora have serrate borders of leaves. But three fossil 

 species represented by leaves with entire borders have been described 

 as Liquidambar from the Tertiary of Europe ; and, though this reference 

 is more or less hypothetical and controversed, it shows, however, that 

 botanists of high standing — linger, Watelet, Massalongo — have con- 

 sidered as probable, at least, the relation of leaves with entire borders 

 to this genus. It is easily seen that the leaves of Aralia Toioneri, de- 

 scribed in this paper (PI. IV, fig. 1), have a relation of shape or general 

 outline to those of Liquidambar integrifolium ; and this apparent simi- 

 larity can but suggest the possible reference of all these and like forms 

 to the genus Aralia. I may admit this reference as probable for the two 

 leaves figured in Cret. FL, PI. XXIX, figs. 8 and 9, which are compara- 

 ble, by their primary nervation, to those of Aralia concreta, sp. nov., 

 PL IV, figs. 2 and 3. But though we have now a large number of speci- 

 mens referable to divers araliaceous types, there is none as yet with 

 leaves divided into lanceolate acute lobes like those which are figured 

 in PL II, Cret. Fl. The reference of these leaves to Sterculia has been 

 proposed also, from analogy of forms to some species of this genus. 

 The presence of one well characterized species of Sterculia in the Creta- 

 ceous flora of New Jersey, where it is in connection with numerous 

 leaves of Magnolia alternans, seems to give a kind of support to this 

 proposition. But in this case, also, I find too evident a difference in the 

 characters of nervation of the palmately-nerved leaves of Sterculia with. 

 those referred to Liquidambar. Even taking as evidence of possible affin- 

 ities the distribution in the same formation of leaves referable to allied 

 genera, we could just as well admit the presence of Liquidambar species 

 in the Dakota group, by the reason that other forms of Hamamelidew, 



