50 CONTRIBUTIONS TO PAL^ONTOLOGY 



inclined to separate these into two species, Myrica torreyi and M. oUongifolia, on the basis of dif- 

 ferences in shape, the forraer with narrowly lanceolate leaves and the latter witla long-elliptic to 

 ovate-lanceolate leaves. I am now convinced, however, from gradations in shape which are 

 apparent in the Medicine Bow collections and in various Upper Cretaceous collections at the U. S. 

 National Museum, that all of these specimens belong to a single species whose leaf characters are 

 amazingly consistent even though somewhat variable in size and shape. In view of the large 

 amount of new material collected, it seems desirable to re-describe the species here. 



Description {Swpplementary) — Leaves linear to narrowly lanceolate to long-elliptic, sym- 

 metrical, narrowed gradually to a long-cuneate base and a narrowly acute tip; length variable 

 from 5 to 15 cm., width from 1 to 5 cm.; average dimensions appear to be about 11 cm. by 2.5; 

 greatest width at the middle of the leaf or slightly below; petiole relatively short, thick, averaging 

 about 2 cm. in length; midrib prominent on the lower surface of the ieaf; secondaries usually 

 inconspicuous, numerous, and closely spaced, leaving the midrib at obtuse angles varying from 50° 

 to 80°, averaging about 70°; secondaries irregularly forked, unbroken, or irregularly joined toward 

 the margin where they meet a prominent intramarginal vein which borders the entire leaf 1 to 2 

 mm. from the edge; indistinct veins join the intramarginal vein to the closely spaced marginal 

 serrations, which may be obscured by sUght curling of the leaf margin; tertiary venation obscure; 

 texture coriaceous. 



Myrica toireyi, as previously conceived by various authors, is widely distributed in the late 

 Cretaeeous sediments of the Rocky Mountain region. It has previously been recorded, usually 

 abundantly, in the Black Buttes, Lance, Laramie, Mesaverde, Fruitland, Fox Hills, and Vermejo 

 floras. Its presence in the Denver and Dawson floras is indicated by the specimens called Myrica 

 sp. and M. torreyi minor which are clearly variants of the normal leaf type. Likewise, Myrica 

 coriacea from the Vermejo formation and M. dubia and M. oblongifolia from the Laramie, which 

 were described as closely similar to M. torreyi, are obviously only variants, a view which seems 

 the more likely because of the previous record of the normal M. torreyi from these same beds. 



This species is an important and diagnostic index species of the late Cretaceous. It has 

 never, to my knowledge, been reported from beds of undisputed Paleocene or younger age. Its 

 characteristics, moreover, are usually well defined and not likely to cause confusion with other types. 



The reference of this fossil species to the genus Myrica is open to question. I have consulted 

 all available herbarium sheets of both eastern and western hemisphere species of Myrica at The 

 New York Botanical Garden, and have failed to find any species whose leaves are comparable to 

 the fossil specimens. The pronounced intramarginal vein observed in the fossil species is never 

 present in the leaves of Myrica; neither are the fine teeth nor the closely set secondary veins. 

 The leaves of several genera of the Myrtacese, on the other hand, are comparable in most respects, 

 differing only, in some cases, in the absence of fine marginal serrations. In the genera Amomis, 

 Colycolpus, Calyptranthes, Eugenia, and Jambosa, for example, most of the species possess leaves 

 of the same general shape and almost identical venation as in the fossil specimens. The closest 

 resemblance observed is with Eugenia jambolana Lam. (sheet No. 5601) and E. {Phyllncalyx) sp. 

 (sheet No. 7559) of Brazil, and with Jambosa jambos (L.) Millsp. (sheet No. 15020) of Colombia; 

 these differ from the fossil leaves only in the absence of marginal serrations. It seems Ukely that 

 Myrica torreyi will ultimately be referred to MyrtophyUum Heer, indicating resemblance to the 

 family Myrtaceae. 



Occurrence — Corson Ranch, Wyoming, Loc. P. 372; north of Walcott, Wyoming, Loc. P. 

 373; Elk Mountain road, Wyoming, Loc. P. 374; Craig, Colorado, Loc. P. 375. 



Collection—V. C. Mus. Pal., Plesiotypes Nos. 1307, 1308, 1309. 



Family JUGLANDACEiE 



Genus JUGLANS Linn6 



Juglans leconteana Lesquereux 



(Plate 3, Fig. 1; Plate 4, Fig. 5) 



Juglans leconteana Lesquereux, U. S. Geol. and Geog. Surv. Terr., Ann. Rept. (1870), 382, 1872; idem (1876), 

 517, 1878; Rept. U. S. Geol. Surv. Terr., vol. 7, 285, pl. 54, figs. 10-13, 1878; Knowlton, U. S. Geol. Surv. 

 Prof. Paper 130, 121, pl. 8, figs. 1-3, 1922. 



This species is represented by 5 complete specimens and several fragments. They are 

 indistinguishable from the specimens figured by Lesquereux and Knowlton from the Laramie and 



