MARYLAND GEOLOGICAL SURVEY 783 



Occurrence. MAGOTHY FORMATION. Deep Cut, Delaware; Grove 

 Point, Cecil County, Maryland. 



Collection. U. S. National Museum. 



ERACHYPHYLLUM MACROCARPUM FORMOSUM Berry 

 Plate LIII, Pig. 1 



Brachyphyllum macrocarpum Berry, 1910, Bull. Torrey Bot. Club, vol. 



xxxvii, p. 183 (non Newberry, 1896). 



? Brachyphyllum macrocarpum Berry, 1911, Ibidem, vol. xxxviii, p. 420. 

 Brachyphyllum macrocarpum formosum Berry, 1912, Ibidem, vol. xxxix, 



p. 392, pi. xxx. 

 Brachyphyllum macrocarpum formosum Berry, 1914, Prof. Paper U. S. 



Geol. Survey, No. 84, p. 106. 



Description. Slender elongated twigs, pinnately branched, covered 

 with medium sized, crowded, appressed leaves, spirally arranged. Leaves 

 bluntly pointed, smooth, thick. 



In the consideration of the various specimens which have been referred 

 to Brachyphyllum macrocarpum, a very considerable variation within 

 certain fixed limits is at once obvious. This variation is usually one of 

 size, the more slender specimens being at the same time smoother. This 

 has been frequently noted by the writer and is commented upon in print by 

 Dr. Knowlton, 1 who in discussing the younger forms from Wyoming sug- 

 gests that the species on the verge of extinction became smaller in its pro- 

 portions. In studying the material from the South Atlantic and Gulf 

 states a constant difference in size was noticed. This may reflect a slight 

 difference in climatic conditions and all of the forms may be interpreted 

 as the variations of a single species; in fact, dewberry's fig. 7 (loc. cit.) 

 from the Earitan formation in New Jersey is approximately the same size 

 as the forms from the Montana group of the West and is associated with 

 the normal, stout club-shaped type. That the variety has no particular 

 stratigraphic significance is indicated by its abundance at a horizon as old 

 as the basal Tuscaloosa of Alabama, and its presence in the Woodbine for- 

 mation of Lamar County, Texas. 



1 Knowlton, Bull. U. S. Geol. Survey, No. 163, 1900, p. 29, pi. iv, figs. 5, 6. 



