FOX HILLS AND LOWER MEDICINE BOW 69 



rather than 3 basal primarics. Thcy cannot be distinguished from the Laramie specimcns which 

 Knowlton called Zizyphu.s hendersoni. The spccimcn of Z. coloradensin , which I have examined 

 at the U. S. National Museum, is clcarly thc same species, since it does not show any trace of 

 upper marginal teeth, as Knowlton suspected. 



This species is at present known only from the Laramie and Medicine Bow formations. 



1 have been unable to find any modern leaves with which this species can be compared. 

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



373; Elic Mountain road, Wyoming, Loc. P. 374. 



Collection—\J . C. Mus. Pal., Plesiotype No. 1358. 



Family VITACE^ 



Genus CISSITES Heer 



Cissites lobatus Dorf, n. sp. 



(Plate 13, Fig.s. 2, 3) 



In the field collcctions there were 27 specimens of this type, which were consistent in shape, 

 average size, and venation. Four of the better specimens were retained for study. 



Descri-ption — Leaves oval to elliptic, widest just below the middle, obtusely wedge-.shaped 

 at the base, and gradually narrowed to a slightly elongate, acuminate tip; length 6 to 9 cm.; width 

 3 to 5 cm.; petiole at least 1.2 cm. long; secondaries tri-nerved from just below the base of the 

 blade, the laterals almost as heavy as the midrib, and given off at an angle of 20°; next pair of 

 secondaries branching from the midrib just below the middle; these and the widely spaced sec- 

 ondaries above are acute, sUghtly curved upward, and forking toward the margin forming loops 

 with the secondaries or their branches above; 3 to 4 prominent forking tertiaries along the lower 

 edge of the lateral basal secondaries, and usually one tertiary well developed from the upper edges; 

 margin entire, palmately lobed by 2 pairs of shallow, narrow, rounded sinuses; central lobe largest, 

 symmetrically oval; lateral lobes smaller and asymmetrical ; texture subcoriaceous. 



This species shows only a general resemblance to other fossil species of Cissites from North 

 America. The closest similarity is with C. colgatensis Brown, which, however, is uniformly smaller, 

 more distinctly lobed, and of an entirely different shape.i The resemblance to C. panduratus 

 Knowlton from the Vermejo formation is also apparent though more remote.^ It is, however, 

 similar to specimens from the Lance of "Converse County," Wyoming, which Knowlton tenta- 

 tively called Ficusf lobata Knowlton in an unpublished manuscript at the U. S. National Museum. 



In the attempt to determine the probable botanical affinities of this type of leaf I have sur- 

 veyed all available herbarium material at The New York Botanical Garden of the following fami- 

 lies: Arahaceffi, Magnohaceie, Moracese, Stercuhaceee, and Vitacete. The practice of referring 

 leaves of this general form to Cissites, implying relationship to the genus Cissus (Vitacese), is in a 

 measure substantiated by the leaf characters of several Uving species of that genus, notably C. 

 rhombifolia (sheet No. 557). A general resemblance was also seen to the variable leaves of 

 Pterospermum proteus BurkiU (sheet No. 10120) of the Sterculiacea;. No exact dupUcate of the 

 fossil specimens has yet been seen in any of the families studied. 



Occurrence — Corson Ranch, Wyoming, Loc. P. 372. 



Collection—lJ. C. Mus. Pal., Type No. 1359, Paratype No. 1360. 



Genus VITIS (Touraefort) Linn6 



Vitis stantoni (Ivnowlton) Brown 



(Plate 17, Fig. 1) 



Vitis slantoni (Knowlton) Brown, U. S. Geol. Surv. Prof . Paper, manuscript, 1937. 

 Castalia stanloni Knowlton, U. S. Geol. Surv. Bull. 257, 147, pl. 19, fig. 4, 1905. 

 Viburnum vulpinum Knowlton, U. S. Geol. Surv. Prof. Paper 98, 92, pl. 18, fig. 1, 1917. 

 Vitis dakolana Berrj', U. S. Geol. Surv. Prof. Paper 185-F, 130, pl. 26, figs. 4-6, pl. 27, 1934. 



There are two specimens from Locality P. 374 which appear to be referable to this species, 

 which Brown has recently sjmonymized as given above. As now known this species occurs in 



' Brown. R. W., U. S. Geol. Surv. Prof. Paper, manuseript, 1937. 



2 Knowlton, F. H., U. S. Geol. Surv. Prof. Paper 101, 274, pl. 49, fig. 10, 1917. 



