340 



SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1<>16. 



12 centimeters broad. The rather deeply heart- 

 shaped base, seven strong ribs, strongly looping 

 tertiaries, and strong, broken nervillcs would 

 make it easy of recognition though it lacks so 

 much of the blade. 



This leaf suggests at once Ficus wardii 

 Knowlton,' from the Montana group at Point 

 of Rocks, Wyo. That species, however, is 

 smaller and has a shallower heart-shaped base 

 and only five instead of seven ribs. The lower 

 or outer ribs in Ficus wardii have numerous 

 regular, parallel tertiary branches quite unlike 

 the tertiaries in the present form. These char- 

 acters should make it easy of recognition in the 

 futm-e. 



Occurrence: Fruitland fomiation, 30 miles 

 south of Farmington and 1 mile east of reserva- 

 tion Ime, San Juan Comity, N. Mex. Lot 75 

 (6956). 



Ficus eucalyptifolia? Knowlton. 

 Plate LXXXVII, figures 1,2. 



Picas eucalyptifolia Knowlton, U. S. Geol. Survey Prof. 

 Paper 101, p. — , pi. 44, figs. 1, 2 (in press). 



The types of this species come from the Ver- 

 mejo fonnation of Rockvale, Colo., and are 

 described and figured in the report cited. The 

 San Juan Basin material embraces a nmnber 

 of leaves that appear to belong to this species, 

 but as they are rather poorly preserved it has 

 seemed best to question the reference. They 

 are, so far as can be made out, of the same size 

 and shape as the types, but the nervation, 

 with the exception of the strong midrib, is 

 obscure. The secondaries appear to be very 

 thin, evenly spaced, and parallel, but their 

 termination near the margin can not be seen. 



Occurrence: Fruitland fonnation, 13 miles 

 south of San Juan River and 1 mile east of 

 Chaco River, San Juan County, N. Mex. Lot 

 23 (6960). 



Family LAtTRACEJE. 



Laurus baueri Knowlton, n. sp. 



Plate LXXXIX, figui'e 5. 



Leaf evidently of thick texture and probably 

 evergreen, lanceolate, narrowed in about equal 

 degree to the wedge-shaped base and appar- 

 ently acuminate apex (actual base and apex 

 not presci'ved) ; margin cntu-e, provided with a 

 thick "cord" wluch makes the actual margm; 

 midrib relatively thick, straight; secondaries 



1 Knowlton^ F. H., Flora of the Montana fonnation: U. S. Geol. Sur- 

 vey Bull. 163, p. 48, pi. 9, fig. 1, 1900. 



very thin, alternate, at an angle of 30° or 40°, 

 much cm-ved upward and disappearing just in- 

 side the margm or each joining by a series of 

 veiy thui loops to the one next above ; nervjlles 

 all veiy much broken and irregular and form- 

 ing different-sized areolae. 



The example figured is the only one observed. 

 It is a nan-owly lanceolate, slightly unequal- 

 sided leaf about 9 centimeters long and a little 

 over 2.5 centimeters wide. It is remarkable in 

 that the margin is formed by a thick fibrous 

 "cord" nearly 1 millimeter in width, wliich 

 otherwise resembles a secondary branch. The 

 midrib is very thick for the size of the leaf, but 

 the secondaries are~ thin and dehcate. The 

 actual leaf substance is retained as a thin mem- 

 branaceous carbonaceous fUm, which shows all 

 the details of the nervation as completely as 

 could be seen in a living leaf. Wlien this car- 

 bonaceous film is removed it is fomid that the 

 details of nervation are very faintly impressed 

 on the matrix. It seems probable, from the 

 thick midrib, the woody marginal "cord," and 

 the faintly impressed secondaries, that the leaf 

 was originally tliick and coriaceous and not 

 unlikely was evergreen. 



Tliis species is of the general type of certain 

 of the leaves referred by Lesquereux - to Laurus 

 socialis, a well-known Tertiaiy form. It differs 

 from that species, however, in its larger size, 

 fewer secondaries, which curve upward for a 

 longer distance, and above all in the presence 

 of the marginal "cord." 



Occurrence: Fruitland formation, 2 miles 

 east of Chaco River, San Juan Basin, N. Mex. 

 Lot 14 (6948). 



Laurus coloradensis Knowlton. 



Plate LXXXVIII, figures 4, 5: 



Laurus coloradensis Knowlton, U. S. Geol. Sirrvey Prof. 

 Paper 101, p. — , pi. 45, fig. 3 (in press). 



The type of tliis species comes from the 

 Vennejo formation at Rockvale, Colo., and is 

 described and figured in the report cited. The 

 two leaves here figured are somewhat smaller 

 than the type but do not appear to differ 

 essentially in any other particular. 



Qccurrence: Fruitland formation, 13 miles 

 south of San Juan River and 1 mile east of 

 Chaco River, San Juan Coimty, N. Mex. Lot 

 23 (6960). 



= Lesquereux, Leo, U. S. Geol. Survey Terr. Kept., vol. 7, p. 21.3, pi. 

 36, flgs. 1-4, 7, 1S78. 



