DESCEirXION OF SPECIES— ACEKACE^ 261 



Fl., p. nij, pi. ii, figs. 1-3; pi. xxiv, fig. 2; pi. x.xix, fig. 8), and wliicli, aoconl- 

 ing to European author.-*, iiiighl rather represent some kind of Aralia. In 

 the saiiic work, 1 liave described as Negundokles a fragnunit of a leaf whose 

 attribution is very doubtful; and from the Creta'ceous of Niediu-shoena, d'Et- 

 tingsiiausen has an Acer antiquus, which lie considers himself as of uncertain 

 generic reference. Hence we have no positive evidence of the presence of 

 Acer, nor of any Aceracea;, in the Cretaceous; and the absence of plants 

 of this order in the Eocene of Euro[)e and of America confirms the non- 

 existence of this group in tiie Cretaceous and the Lower Tertiary. Tht; 

 oldest rei)resentatlve ui Acer appears in the Armissan of France, where it is 

 extremely rare; the genus becomes more predominant in the Lower Miocene, 

 and has its largest preponderance in the Middle and Upper Miocene. Li 

 North America, as remarked above, we know only two Miocene species, one 

 from Carbon, the other from Alaska. Other kinds of ^feyYffeff", Sapindus and 

 Ncgundo, have also representatives in the same formation. They become, 

 liowever, more numerous in more recent stages of the Tertiary; for the Upper 

 Green River group abounds in leaves oi' Sapindi/s ; it has, besides, one species 

 of Ace)\, identified in the Pliocene of California, which has two kinds of Maple 

 leaves in the fifty species known from this grouj). It is very probable that 

 Acer will l)c found amply represented in the Pliocene of the Mississippi liiver. 



Acer I r i I o b a t u (Bi var. p r o «i <i c t (■ iii ! , Al. Br. 



Plate XLVIII, Figs. 2, 3 a. 



Jcir trilohatiim, Al. Br., N. Jahrb. v. Brouu & Leoub., 1845, p. 172. — Uiig., Cblor. Proto};., \i. l'.)0, pi. xli, 

 figs. 1-8.— Heer, Fl. Tert. Helv., i, p. 48, jil. ii, figs. 3, 4, 6, 8; iii, p. 47, pi. ex, figs. 10-21 ; cxi, 

 figs. 1,2, 0-14, 16, IS-fil ; cxii,figs. 1-8, 11-10 ; cxiii ; cxiv ; cxv ; cxvi, figs. 1-3; p. 197, pi. civ, 

 figs. 9, 10.— Uug., Foas. Fl. v. Kiimi, p. 49, pi. xii, figs 28-30 —Sap., f;t., iii, p. 101.— Liulw., 

 Palajout., viii, p. 127, pi. 1, figs. 1-5; li, figs. 4-11; Iii, figS; 2, 4-7; liii, fig. 0. — O. Web., Pa- 

 leont., ii, p. 195.— Etf., Fos.s. Fl. v. Bil., iii, p. 18, pi. i, fig. 14; xliv, figs.l-.5, 7-9, 12-15.— 

 Lcsqx., Annual Report, 1872, p. 388; 1873, p. 408. 



rhiiUihs trilohatus, Stornb., Fl. il. Urw., i, p. 42, pi. I, fig. 2.- 



I'hijllikx Johatus, Stcrub., ibid., p. 39, pi. xxxv, fig. 2. 



-icrr IriciiHpidatum, Al. Br., I. c, p. 172. 



Acer patens, Al. Br., Stizenb. Verz., p. 84, 



Acer productum, Al. Br., N. Jalirb., /. c, p. 172.— Uug., Cblor. Protog., p. 131, pi. xli, figs. 1-9 ; Stizoub. 

 Vcrz., p. 84. 



Acer ritifoliitm, Ung., Cblor. Protog., p. 133, pi. xliii, fig. 10?. 



Acer megahptcrix, Ung., Sillog., iii, p. 47, pi. xv, fig. 0. 



Accrues filici/oHun, Viv., M£ui. Soc. 0<5ol. do Fr., 1833, i, p. 131, pi. ix, fig. 5f. 



Arerites dciHrdiliis, Mass., Fl. Foss. tl'It; 1. Mer., p. 4, pi. ii, fig. 7. 



Liquidambur Si'iirabdliaiuiiii >-t L. affine, Mass., Fl. Foss. Seiiog., pi. ii, fig. 1 ; pi. iii, lig. fi. 



I'lataiiiis ciimifolia, (ioepp., Seboss. I'l., 1)1. xii, fig. 1. 



Leaf comparatively large, deeply trilobate, narrowed to a long petiole; lobes sbarply acuniiuato, 



tbe middle twice as long as tbe lateral occs; borders dentate. Fruits small; nutli ts obovate; wings 



oblong, obtuse. 



The characters oi this leaf, the onK' one sat isiiictoiiK' iiri'srived from 



