74 FOSSIL FLORA OF THE JOHN DAY BASIN, OREGON. [Hri,i..204. 



AcKR DIMOKrilUM Les(}. 



AcKu ])i.M()Ki'iirM Ia'S(|.. I'rnc. I". S. Nat. I\Ins., Vol. XI, \). h"), I'l. IX, tig. 1, ]<SS8. 



Locality. — Van HorrTs Viinch, about i!3 miles west of Mount Vernon, 

 Grant County, Oregon. Collected })y Maj. Charle.s E. Bendire (U. S. 

 Nat. Mus., No. 2415). 



Acer Merriami n. sp. 



V\. XIV, fig. 7. 



AfEu II. Hp., Knowlton in ]\Ierriani, Univ. Cal., Bull. Dept. Geo]., Vol. II, Xo. 9, 

 p. 309, 1901. 



Leaf coriaceou.s in texture, palmatel^v deeply three lolled, the lobes 

 broad, roughly ovate in shape, of approximately the same size, lateral 

 lobes at a low angle with the central lobe; all margin coarsel}' and 

 irrcgularh^ toothed, l)eing provided with low, irregular, mosth^ sharp- 

 p :)inted teeth; petiole long, very thick; midrib thick, with six or more 

 pairs of alternate, strong secondaries which end in the large teeth of 

 the central lobe, and have smaller branches which pass to other mar- 

 ginal teeth; lateral ribs nearly as strong as the midrib, at a low angle, 

 each with al)out seven pairs of alternate secondaries passing to the 

 large teeth, and those on the lower side especially w ith short branches, 

 which end in marginal teeth; nervilles numerous, thin, mainly percur- 

 rent and at right angles to the secondaries; liner nervation forming a 

 rather coarse, irregularly quadrangular network. 



The example iigui'ed is the only one that has thus far been found. 

 It is a large, deeply three-lobed leaf about 12 cm. long, exclusive of 

 the petiole (of which 2.5 cm. in length is preserved), and about 14 cm. 

 broad. All three lobes are of approximatel}'^ the same size, and all 

 are irregularly toothed, the margin being provided with low, sharp- 

 pointed teeth. The nervation is beautifull}" preserved. 



Maples are abundant in these beds, and many leaves, fruits, and 

 branches have been obtained. The leaf under consideration is markedly 

 different from Aeei' Be'iidiTel^ which is perhaps the most abundant 

 species present, ])ut may possibly be a very broad, coarsely toothed 

 form of A. (JiniorpJinin. The latter species is described by its author 

 as ])eing prolonged at l)ase into two small lobes which open like wings 

 on each side of the midrib. The lateral ribs, therefore, arise at some 

 distance above the top of the petiole in the broad, basal portion of the 

 ))lade. In the leaf before me there is-no indication of the ))asul lobes 

 that are so conspiuous in ^1. dhnorphuDi.^ and the ri))s appear to arise 

 at the top of the petiole and at the very base of the blade. Further, 

 the lobes are doul)ly dentate — that is, have large, irregular teeth or 

 lobes, the margins of which are provided with low^ teeth. Therefore 

 it seems most logical to regard them as distinct, at least for the present. 



