DESCRIPTIONS OF SPECIES. 69 



but specimens subsequently found have made it seem advisable to regard them all as 

 belonging to a distinct species, with the secondary nervation at a more acute angle of 

 divergence from the midrib and with a more elongated or attenuated upper portion 

 than in L. primsevum. 



In some respects these leaves are similar to some of those included in the genus 

 Liriodendropsis, and it is possible that they may ultimately have to be so considered. 

 Our fig. 1 1 is to be specially noted in this connection. 



Locality: Glen Cove, Long Island, PI. XXI, fig. 9. Collected by Arthur Hol- 

 lick. Specimen in Mus. New York Bot. Gard. 



Gay Head, Marthas Vineyard, PL XXI, figs. 10, 11. Collected by David White. 

 Specimens in U. S. Nat. Mus. 



Genus Liriodendropsis Newberry. 



Genus Liriodendropsis Newberry gen. nov., Mon. U. S. Geol. Survey, vol. 26 (Fl. Amboy Clays), 1895 (1896), 

 p. 82. 



In this genus Newberry includes leaves of considerable variation in form v/hich 

 he originally described as a single species under Liriodendron a , and says (loc. cit.) : 



I have thought it best to distinguish by a new generic name a group of leaves which are numerous in the 

 Amboy clays and the Atane beds of Greenland. They have been hitherto included in the genus Liriodendron 

 by Professor Heer and myself; but while they are evidently related to the tulip tree, their simple ovate or 

 lanceolate form, relatively small size, and strongly marked, reticulated nervation separate tnem into a group by 

 themselves, possessing characters which seem to have more than a specific value. 



Since the date Newberry wrote the above a large amount of new material has 

 been collected, which includes not only many which are identical with those which he 

 described, but others which, although differing in certain particulars, are so closely 

 similar that they should all be regarded as at least generically related, although what 

 the botanical relationship of the genus may be is a question which we are not yet in a 

 position to answer, and it must be admitted that in this connection the new material, 

 with its multiplicity of new forms, has added to our perplexity instead of assisting us 

 in arriving at any satisfactory conclusion. 



Heer considered certain leaves from the lower Atane beds of Greenland, iden- 

 tical with those subsequently included by Newberry under Liriodendropsis simplex y b 

 to be varieties of Liriodendron Meekii Heer, and they were so described and figured 

 by him, together with other forms which he regarded as allied, including LArioden- 

 dron primsevum Newb., PTiyllites obcordatus Heer, and Leguminosites Marcouanus 

 Heer. c This segregation of spacies was criticised by Newberry in his discussion of 

 the genus Liriodendropsis (loc. cit.), but the actual or possible relationship of most 

 of them to Liriodendron was affirmed. 



The question of the affinity of some of these forms with Liriodendron was dis- 

 cussed at some length by Theodor Holm in a paper entitled "Notes on the Leaves 



aL. simplex., Bull. Torrey Bot. Club, vol. 14, 1887, p. 6, pi. 42, figs. 2-4. 



b Mon. U. S. Geol. Survey, vol. 26 (Fl. Amboy Clays), 1895 (1896), p. 83, pi. 19, figs. 2, 3; pi. 53, figs. 1-4, 7. 

 cFl. Foss. Arct.,vol. 6 (abth.2),1882, p. 87, pi. 18, fig. 4c; pi. 22, figs, la, lb, 2-13; pi. 23, figs. 3-8; pi. 25, fig. 5a; pi. 45, 

 figs. 13a, 13b. 



