FOX HILLS AND LOWER MEDICINE BOW 57 



Knowlton.' The tj'pe spccimens of both of thcse spccies are not distinguishable in any way from 

 my specimens nor from the specimen of Cornus prmmpressa. I have not seen the actual specimen 

 of Rhamnites knowltoni from the Lance formation, but the figure seems quite unlike the type 

 specimens of this species from the Eocene of the Gulf Coast,^ and is not distinguishable from the 

 specimens here referred to Ficus crossii. Such a reference is substantiated by the presence of 

 several indistinguishable leaves in a coUection which I recently made from the lower Lance near 

 Ekalaka, Alontana. In view of the discovery of more complete specimens than hitherto known, 

 it seems desirable to ampHfy the descriptions previously given of this species. 



Descripiion {Supplementary) — Leaves elHptic to oval, with a broadly cuneate base and 

 abruptly short-acuminate tip; lcngth 8 to 10 cm.; width 5 to 6cm.; midrib thick in depth, especially 

 below, straight or very slightly curved; secondaries about 10-12 pairs, mainly alternate, at an 

 angle of about 60° near the base to as low as 35° near the apex, slightly curved upward, unbranched, 

 camptodrome, arching upward just inside the margin; tertiary veins fairly strong, mainly un- 

 broken, at angles of 90° to thc midrib ncar the apex to as low as 65° to the midrib in the lower half ; 

 finer veins forming an irregular meshwork; margin entire; texture firm. 



This species as now known is present in the Mesaverde, Colgate, Laramie, lower Lance, and 

 lower Medicine Bow formations, with the closely related Rhamnites knowltoni occurring in the 

 Eocene of the Gulf Coast. There do not appear to be any Fort Union species with which conf usion 

 might result. 



Among living forms there appear to be very few species of Ficus with leaves of this general 

 character. I have surveyed the foUowing genera at The New York Botanical Garden as alterna- 

 tive possibilities for comparison: Anona (Anonacese), Cornus and Nyssa (Cornacese), Ficus 

 (Moraceae), Magnolia (Magnohaceffi), Rhaninus (Rhamnaceae), Cephalanthos (Rubiacese), and 

 Diospyros (Ebenaceee). The cIo.sest resemblance among these genera was with Magnolia, 

 particularly M. virginiana L. (= M. glauca L.) and the smaller leaves of M. grandiflora L. 



Occurrence — Corson Ranch, Wyoming, Loc. P. 372; Elk Mountain road, Wyoming, Loc. 

 P. 374; Craig, Colorado, Locs. P. 375, P. 376. 



Collection—ll. C. Mus. Pal., Plesiotype No. 1325. 



Ficus tesselata Lesquereux 



(Plate 6, Fig. 2) 



Ficus tesselata Lesquereux (MS.), Knowlton, U. S. Geol. Surv. Prof. Paper 101, 266, pl. 41, fig. 5, 1917. 



The collections contain only 2 fairly complete specimens and several fragments of this type 

 of leaf . These are essentially similar to the figured and type specimen of Ficus tesselata from the 

 Vermejo formation. Knowlton has pointed out the resemblance to Rhaninus salicifolius Les- 

 quereux,' from which it differs decidedly in its shape, its fewer, more acute secondaries, and its 

 open tertiary venation. It seems even closer to Laurus lanceolata Knowlton from the Laramie 

 and Dawson formations.^ The known specimens of this species, unfortunately, are too few and 

 too fragmentary to make possible a detailed comparison. 



Knowlton has recorded Ficus tesselata also from the Lance formation in an unpublished 

 manuscript at the U. S. National Museum. 



I can see httle justification for the reference of this species to the genus Ficus. In a complete 

 survey of both eastern and western hemisphere species of Ficus at The New York Botanical 

 Garden I was unable to find any leaf forms with comparable characters. The family Lauraceae, 

 on the other hand, contains many comparable leaf forms, chiefly in the genus Nectandra (cf. 

 N. glauca ^ and N. cuspidata * of South America). 



Occurrence — Corson Ranch, Wyoming, Loc. P. 371; Elk Mountain road, Wyoming, Loc. 

 P. 374. 



Collection—\]. C. Mus. Pal., Plesiotype No. 1326. 



' Knowlton, F. H., U. S. Geol. Surv. Prof. Paper 130, 139. 160, 1922. 

 ' Berry, E. W.. U. S. Geol. Surv. Prof. Paper 131, 16, pl. 12, fig. 7, 1923. 



3 Lesquereux, Leo, Rept. U. S. Geol. Surv. Terr., vol. 7, 282, pl. 53, figs. 9, 10, 1878; Knowlton, F. H., U. S. Geol. Surv. 

 Prof. Paper 130, 154, pl. 15, fig. 4, pl. 19, fig. 2b, 1922. 



» Knowlton, F. H., U. S. Geol. Surv. Prof. Paper 130, 143, pl. 21, fig. 7, 1922; idem, Prof. Paper 155, 85, pl. 38, fig. 9, 1930. 

 ' See sheet No. 708, Boli^na, at the Princeton University herbarium. 

 ' See sheet No. 707, Mapiri, Bolivia. 



