FOX HILLS AND LOWER MEDICINE BOW 51 



Black Buttcs floras. They are similarly indistinguishable froin the original types consulted at 

 the U. S. National Museum. These were apparently misplaced at the time Knowlton wrote 

 Professional Paper 130, but have since been located. 



Both Lesquereux and Knowlton have considered the possibility that these leaves might 

 represent variants of Juglans rugosa Lesquereux or J. rhamnoides Lesqucrcux. The continued 

 discovery of leaves of the J. leconteana type, and the absence of leaves of the formcr types in the 

 same strata tend to corroborate the maintenance of the latter species as distinct. The reference 

 to the genus Juglans seems to be based on insufRcient evidence. 



I have noted a close resemblance of the speciraens to the leaves of Maclura (Moracese), 

 especially M. aurantiaca Nutt., and Apocijnum (Apocynaceffi), especialiy A. pubcscens (?). Until 

 some positive grounds are estabhshed for a change in name it seems best, however, to retain the 

 old one. 



Occurrence — North of Walcott, Wyoming, Loc. P. 373; Elk Mountain road, Wyoming, Loc. 

 P. 374. 



Collection—V. C. Mus. Pal., Plesiotypes Nos. 1310, 1393. 



Juglans newberryi Knowlton 

 (Plate 4, Fig. 4) 

 Juglans neirberryi Knowlton, U. S. Geol. Surv. Prof. Paper 130, 120, pl. 20, figs. 8-10, 1922. 



The single specimen figured is the only one of this type in the collections. It is identical with 

 the specimens of this species from the Laramie formation. Although Knowlton described the 

 margins of his specimens as entire, the type specimens at the U. S. National Museum are some- 

 what obscure along the margins, like the specimen here discussed, and appear to have a few fine 

 serrations in the upper half of the leaf. 



These leaves resemble somewhat those of Juglans crossii Knowlton from the Green River 

 formation,' differing mainly in the marginal characters and the more closely spaced secondary 

 veins. The refercnce to Juglans may be correct, although several species of Sapindus have leaves 

 which are virtually identical. 



Occurrence — Elk Mountain road, Wyoming, Loc. P. 374. 



Collection—lS. C. Mus. Pal., Plesiotype No. 1311. 



Juglans prserugosa Knowlton 

 (Plate 4, Fig. 6) 

 Juglans prccrugosa Knowlton, U. S. Geol. Surv. Prof. Paper 130, 121, pl. 5, fig. 2, pl. 21, fig. 5, 1922. 



This type of leaf is represented only by the complete specimen figured and several fragments. 

 I was at first inclined to refer these to Juglans denveriana Knowlton ^ or J. rugosa Lesquereux ^ but 

 find what seem to be important differences in shape, margin, and venation. In these characters 

 the specimen is indistinguishable from the type and figured specimens of J. prarugosa from the 

 Laramie, and fits its description perfectly. Knowlton has already reported the occurrence of 

 this species in the Medicine Bow formation of the same region from which my collections were 

 made.^ I have not bcen able to match these specimens with any modern leaves. 



Occurrence — ?Corson Ranch, Wyoming, Loc. P. 371; Craig, Colorado, Loc. P. 376. 



Collection—\] . C. Mus. Pal, Plesiotype No. 1312. 



Family FAGACEiE 



Genus DRYOPHYLLUM Debey 



Dryophyllum subfalcatum Lesquereux 



(Plate 5, Figs. 1, 2, 6) 



Dryophyllum (Quercus) suhjalcalum Lesquereu-X, U. S. Geol. and Geog. Surv. Terr. BuU., vol. 1, 379, 1876; 



idem, Ann. Rept. (1874), 301, 1876; Rept. U. S. Geol. Surv. Terr., vol. 7, 163, pl. 63, fig. 10, 1878; Knowl- 



ton, U. S. Geol. Surv. Bull. 163, 41, 1900; Washington Acad. Sci. Proc, vol. 11, 211, 1909; Brown, U. S. 



Geol. Surv. Prof. Paper, manuscript, 1937. 

 Dryophyllum aquamarum Ward, U. S. Geol. Surv., 6th Ann. Rept., 551, pl. 37, figs. 3-5, 1886; idem, Bull. 37, 



26, pl. 10, figs. 2-A, 1887; Knowlton, U. S. Geol. Surv. Prof. Paper 101, 299, pl. 70, fig. 2, 1917. 



> Lesquereux, Leo, Rept. U. S. Geol. Surv. Terr., vol. 7, 289, pl. 58, fig. 1 ( = J. denticulala Heer), 187S. 

 2 Knowlton, F. H., U. S. Geol. Surv. Prof. Paper 155, 44, pl. 12, figa. 1, 2, pl. 13, figs. 2-t, 1930. 

 s Lesquereux, Leo, Rept. U. S. Geol. Surv. Terr., vol. 7, 286, pl. 54, figs. 5, 14, pl. 55, figa. 1-9, 1878. 

 * Knowlton, F. H., U. S. Geol. Surv. Prof. Paper 130, 100, 1922. 



