MARYLAND GEOLOGICAL SURVEY 787 



Sptienolepidium dentifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. 

 xv, 1889, p. 258, pi. cxxviii, figs. 2-6; pi. cxxix, fig. 6; pi. cxxx, figs. 

 4-6, 10. 



Sequoia ambigua Bozzi, 1891, Bol. Soc. Geol. Ital., vol. x, p. 373, pi. xv, fig. 4. 



Sequoia ambigua Nathorst, 1893, in Felix and Lenk, Beitr. z. Geol. u. Pal. 

 Repub. Mexico, ii Theil, 1 Heft, p. 51, figs. 1-3. 



Sequoia ambigua Hollick, 1895, Bull. Geol. Soc. Am., vol. vii, p. 13. 



Sequoia gracilis Fontaine, 1899, in Ward, 19th Ann. Kept. U. S. Geol. Sur- 

 vey, pt. ii, p. 675, pi. clxvi, fig. 2 (non Heer). 



Sequoia ambigua Uhler, 1901, Trans. Md. Acad. Sci., vol. i (1892), p. 207. 



Sequoia ambigua Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. 

 xlviii, 1905, pp. 272, 281, 538, 555, pi. Ixix, fig. 6; pi. ex, fig. 13. 



Sptienolepidium dentifolium Fontaine, 1906, in Ward, Mon. U. S. Geol, Sur- 

 vey, vol. xlviii, 1905, pp. 484, 528, 538, 546, 555. 



Arthrotaxopsis expansa Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, 

 vol. xv, 1889, pp. 533, 535, 538, 555, 573, pi. cix, figs. 12, 13 (non pp. 504, 

 520, 547, 571). 



Sequoia ambigua Hollick, 1907, Mon. U. S. Geol. Survey, vol. 1, p. 41, pi. iii, 

 figs. 7, 8. 



Sequoia ambigua Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, 1907, 

 p. 126. 



Sequoia ambigua Berry, 1910, Bull. Torrey Club, vol. xxxvii, p. 20. 



Sequoia ambigua Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 310. 



Sequoia ambigua Berry, 1911, Md. Geol. Surv., Lower Cretaceous, p. 449, pi. 

 Ixxviii, figs. 1-7. 



Description. " S. ramis elongatis, foliis omnino tectis, ramulis alternis, 

 gracilibus, foliis decurrentibus, brevibus, crassiusculis, falcato-incurvis, 

 apice acuminatis, uninerviis, strobilis globosis, squamis peltatis, planius- 

 culis." Heer, 1874. 



Eemains of the foliage of this species are distinguishable from those 

 of contemporaneous conifers, which occur in the beds with them, by the 

 relatively short and very stout, acuminate, falcate or recurved, decurrent 

 leaves. 



The cones are spheroidal and consist of relatively few, short scales with 

 longitudinally striated peduncles and suddenly expanded, quadrangular, 

 peltate, umbilicate tips. These cones are abundant in the Lower Creta- 

 ceous of Maryland, occurring usually as detached ferruginized mud casts, 

 and are fully described in the writer's account of the Lower Cretaceous 

 flora of Maryland. 



As recorded in the literature cited above, Sequoia ambigua is widely 

 distributed geographically and it has an equally great geological range. 



