112 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



Crataegus flavescens Newb. 

 PL XL VIII, fig. 1. 

 Proc. U. S. Nat. Mus., Vol. V (March 21, 1883), p. 507. 



"Leaves small, about 1 inch in length and breadth; lobed; lobes 

 rounded and bearing a few teeth or crenulations ; the summit of the leaf 

 trilobed, with two lateral lobes below on either side." 



Several small, lobed leaves are contained in the collection made by 

 Rev. Thomas Condon, which bear such resemblance to those of some 

 species of Crataegus that we seem to be justified in referring them to this 

 genus. Of these the one figured is the most complete in outline; this in 

 its general proportions and markings approaches closely to the leaves of 

 C. flava Ait., but in that species the leaves are usually somewhat larger and 

 the lobes are set with several acute teeth. 



Eighteen fossil species of Crataegus have been described, and of these 

 three from the Tertiary deposits of North America, namely, C. antiqua Heer 

 (Fl. Foss. Arct, Vol. I, p. 125, PI. L, figs. 1, 2), C. Warthana Heer, and 

 C. (equidentata Lesq. (Tert. FL, p. 297, PI. LVIII, figs. 4, 4a); but these 

 are much larger and have rhomboidal and undivided leaves ; indeed, it is 

 not certain that they all belong to the genus Crataegus. 



Of foreign species there is none with which this is likely to be con- 

 founded. C. dyssenterica Mass. (Fl. Foss. Senigall, p. 414, PL XIX, fig. 1), 

 is similarly lobed, but the. leaves are larger and much more deeply cut, 



The resemblance of the leaves before us to those of the living C. flava 

 is so close that it is quite possible that the present is the derivative from the 

 ancient species, a possibility suggested in the specific name chosen. 



Formation ai%d locality : Tertiary (Miocene). Bridge Creek, Oregon. 



Pruntjs variabilis Newb. 



PI. LII, figs. 3 and 4 (in part), 5. 

 Proc. IT. S. Nat. Mus., Vol. V (March 21, 1883), p. 509. 



"Leaves short-petioled, very variable in form; lanceolate or broadly 

 lance-ovate, 2 to 3 inches long by 1 to 2 inches wide; acuminate at the 

 summit, wedge-shaped at base; margins thickly set with minute, acute, 

 appressed teeth." 



Numerous leaves, which evidently belong to the genus Prunus, occur 



