222 



SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1921. 



leaves diverging from the typical Sassafras cre- 

 tace.um, the form shown in Plate VIII, figure 1, 

 of "Later extinct floras" is removed a slight 

 distance by the shortening of the blade, the 

 thickening of the primaries and secondaries, and 

 the shortening and rounding of the lobes (Sassa- 

 fras ohtusum) ; while a smaller leaf would be its 

 logical descendant : and from theseleaves to those 

 referred to the typical Cwsites salisburiaef alius 

 is but a step. In the third series of leaves diverg- 

 iiig from the typical Sassafras cretaceam the 

 leaf has its lobes much produced, narrow, and 

 running to a sharp point, as in the beautiful 

 leaf shown on Plate VII, figure 1, of "Later 

 extinct floras," which, however, is still refen-ed 

 to Sassafras cretacenm. Lesquereux's Sassa- 

 fras acutilohiim does not differ greatly from the 

 leaf just mentioned except in the direction of 

 the lobes, which is a questionable specific char- 

 acter. From this leaf it is no great jump to 

 those trilobed forms which are refeired to Ara- 

 lia wellingtoniana , the chief difference being in 

 the margin. Thus we have an interrelated 

 series connecting those leaves which seem to 

 show affinity to Sassafras with those which 

 suggest Platanus, on one hand, and ^^nth others 

 which suggest Cissiles and Arnlia, on the other. 



While it may be considered probable that 

 biologically the forms mentioned in the forego- 

 ing paragraphs, as well as others not cited, 

 represent the variations of a single species of 

 Upper Cretaceous tree or at least represent 

 the leaves of closely afhliated species, it seems 

 best with reference to systematic and especially 

 stratigraphic paleobotany that most of the 

 dift'erentiations instituted by Lesquereux be 

 perpetuated. Consequently the present series 

 is limited to the typical material as defined 

 and illustrated by the original describer. 



Falling within these limits are a number of 

 occurrences in the true Dakota sandstone and 

 the Raritan and Magothy formations of the 

 Atlantic Coastal Plain. The Cheyenne sand- 

 stone has furnished four specimens obtained 

 near Medicine Lodge River, 2 miles west of 

 Belvidere (2224), and one specimen from the 

 left bank of the middle branch of Champion 

 (Wildcat) Draw, half a mile south of Belvidere 

 (2229). 



POSITION UNCERTAIN. 



Genus FEISTMANTELIA Ward. 



Feistmantelia oblonga Ward. 



Plate XLVII, figures 4, 5. 



Feislmanlelia oblonga Ward, U. S. Geol. Survey Nineteenth 

 Ann. Kept., pt. 2, p. 693, pi. 169, fig. 19, 1899. 



In not proposing a specific name for the form 

 of this genus found in the Cheyenne sandstone 

 I emphasize the fact that the term Feistmantelia 

 denotes merely a form of preservation and that 

 the objects to which it is applied lack either 

 stratigraphic or botanic value. 



This genus and in fact the nominal species 

 Feisfmantflia oblonga were founded by Ward in 

 1899 for the reception of certain casts of obscure 

 affinities, but evidently of a vegetable nature, 

 from the Fuson formation of eastern Wyoming. 

 No diagnosis was attempted, but an extended 

 discussion was given of somewhat similar forms 

 figured by previous authors from various 

 geologic horizons. The American Cretaceous 

 forms referred to this genus may be character- 

 ized as showing a rather close-set series of 

 elliptical, fusiform, or cigar-shaped convex casts 

 of concave cavities formed by the rhytidosis 

 of various plant tissues. They vary consider- 

 ably in size, from 0.6 to 2.5 centimeters in 

 length by 0.35 to 1.0 centimeter in width, and 

 are arranged in an irregular spiral, the irre- 

 gularity being perhaps due to compression. 

 They are thus overlapping or alternate in a 

 horizontal direction and more or less linear in 

 a vertical direction. 



Somewhat similar remains occur at widely 

 separated geologic horizons, and comparable 

 objects with the markings inclined to be 

 rhomboidal in form are not rare in the New 

 Jersey Triassic deposits, where they are, ac- 

 cording to Newberry ,^^ the decorticated trunks 

 of some conifer, possibly Palissya. Similar 

 remains are figured by Schauroth ^' as trunks 

 of Voltzia coburgensis and by Blanckenhorn^' as 

 trunks of Voltzia heterophylla. 



3« Newberry, J. S., U. S. Geol. Survey Mon. 14, p. 94, pi. 2ij, figs. 1, 2, 

 1888. 



3' Schauroth, Deutsch. geol. Gesell. Zeitschr., Band 4, p. 539, 1852. See 

 Schenk, August, Palaeontographioa, Band 11, p. 308, pi. 4ii, fig. 2, 1S64. 



3s Blanckenhom, Max, Palaeontographica, Band 32, p. 135, pi. 22, 

 flgs. 18-20, 1886. 



