Maryland Geological Survey 447 



The slight variations from specimen to specimen and the varying 

 conditions of preservation in the twigs of this species throughout the 

 Potomac, together with the detached and more or less macerated cones 

 furnished the basis for six species and varieties of Fontaine and Ward, 

 but these are obviously not specifically distinct from one another. 



Occurrence. — Patuxent Formation. Fredericksburg, Telegraph 

 Station (Lorton), Dutch Gap, Virginia; Springfield, Maryland. Arun- 

 del Formation. Eeynolds Ore Pit, Maryland. Patapsco Formation. 

 Near Brooke, Virginia. 



Collection. — IJ. S. IsTational Museum. 



Sequoia rigida Heer 



Plate LXXVIII, Fig. 8 



Sequoia rigida Heer, 1873, Fl. Foss. Arct., Band iii, Abth. ii, pp. 80, 91, 102, 

 128, pi. xxii, figs. 5g, 11a; pi. xxv, fig. 6; pi. xxvii, figs. 8-14; pi. 

 xxxviii, figs. 9a, 10. 



Sequoia rigida Schenk, 1875, Palseont., Band xxiii, p. 168, pi. xxix, figs. 8, 9. 



Sequoia rigida Heer, 1882, Fl. Foss. Arct., Band vi, Abth. ii, p. 52, pi. vii, 

 figs. 10-12; pi. viii, fig. 7; pi. xxi, fig. Ic; pi. xxiv, fig. 3b. 



Sequoia rigida Heer, 1883, Fl. Foss. Arct., Band vii, p. 13, pi. liii, figs. 5-7. 



Sequoia subulata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 



245, pi. cxvii, fig. 7; pi. cxviii, figs. 5, 6 (non Heer). 



Sequoia rigida Fontaine, 1890, Mon. U. S. Greol. Survey, vol. xv, 1889, p. 



246, pi. cxviii, fig. 3; pi. cxxi, fig. 2; pi. cxxvi, fig. 2; pi. cxxx, fig. 3. 

 Sequoia rigida Knowlton, 1905, in Stanton and Martin, Bull. Geol. Soc. 



Amer. vol. xvi, p. 408. 

 Sequoia rigida Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 



1905, p. 219. 

 Sequoia sul)ulata Fontaine, 1906, in Ward, IMd., pp. 486, 571. 

 Sequoia rigida Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 309. 



Description. — " S. foliis coriaceis, rigidis,^linearibus, apice acuminatis, 

 patentibus, rectis, uninerviis, transversim subtilissime regulosis, basi non 

 angustatis, adnato-longe decurrentibus.'^ — Heer, 1873. 



This species was described by Heer from the Kome beds of Greenland 



although he subsequently pointed out that it was more abundant in the 



Atane beds. He compared it with Sequoia Woodwardii (Carr.) Schimp., 

 29 



