Maryland Geological Survey 441 



Following Seward's suggestion/ the cones that Fontaine referred to this 

 species are considered to belong to Sphenolepis Kurriana (Dunker) 

 Schenk;, as are also some of the leafy twigs which Fontaine identified 

 as Arthrotaxopsis, and a number of the recorded occurrences of the latter 

 have also been found to belong to Sequoia amhigua Heer, 



The present is another of the several species which may be compared 

 with the foliage from the Lower Cretaceous of Greenland which Professor 

 Heer referred to Cyparissidium. 



Occurrence. — Patuxent Formation. Eoadside near Potomac Run, 

 Telegraph Station (Lorton), Trents Eeach, Cockpit Point, Dutch Gap, 

 Virginia; Springfield (?), Maryland. Arundel Forhiation. Langdon 

 (common). District of Columbia; Tip Top (?), Maryland. 



Collection. — U. S. ISTational Museum. 



Arthrotaxopsis grandis Fontaine 

 Plate LXXVI, Plate LXXVII, Fig. 6 



Arthrotaxopsis grandis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 240 (pars), pi. cxiv, figs. 1-3; pi. cxvi, figs. 1-4; pi. cxxxv, 



fig. 10. 

 Arthrotaxopsis tenuicaulis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 241, pi. cxiv, figs. 4, 5; pi. cxv, fig. 4; pi. cxvi, fig. 6; pi. 



cxvii, fig. 2. 

 Arthrotaxopsis pachyphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 242, pi. cxv, figs. 1, 3; pi. cxvii, figs. 1, 3-5. 

 Arthrotaxopsis tenuicaulis Fontaine, 1899, in Ward, 19tli Ann. Rept. U. S. 



Geol. Survey, pt. ii, p. 674, pi. clxiv. 

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



vol. xlviii, 1905, p. 546. 

 Arthrotaxopsis tenuicaulis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., 



vol. xlviii, 1905, pp. 516, 520, 538, 546, 571. 

 Arthrotaxopsis grandis Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 296. 



Description. — Leafy twigs elongate and slender, especially the distal 

 ones which are extremely attenuated and unbranched or sometimes 

 dichotomously branched. Main branches alternate, much branched, 

 apparently in a single plane. Distal twigs crowded, somewhat fastig- 

 iate. Leaves usually thin, closely appressed, elliptical to rhombic in 

 shape, slightly keeled, acute. Phyllotaxy spiral. Cones small, ovoid, 



^ Seward, Wealden Fl., pt. ii, 1895, p. 201. 



