DESCRIPTION OF THE SPECIES. 247 



This plant differs from all the other Sequoias in the peculiar crowding 

 of the leaves at tlieir bases, which seeuis to arise from a grouping in whorls, 

 the groups being separated by a comparatively considerable interval. 



Sequoia gracilis Heer. 



Plato CXXVI, 1-iKs. :?, 4. 



Ileer' describes S. f/racilis as Sequoia, with alternate branches, approx- 

 imate ; leaves scale-shaped, imbricated, subfalcate, decurrent at base, and 

 without a midnerve. 



This description and the figures given in PI. XXII, Figs. 1-10, Pi. 

 XVIII, Fig r, agree closely with some of the Potomac plants. 



Localities: 72d mile-post, near Brooke, common; bank near Brooke, 

 rare. 



Tlie specimens are found in small bits and fragments of twigs, and 

 these are among the most abundant fossils at the first-named locality. 

 Such bits as those given in Fig. 3 are the most common. 



Sequoia delicatula, sp. nov. 



Plate CXXI, Fig. :i. 



Principal twigs slender, penultimate and ultimate ones all in one 

 plane, minute, short, closely placed, alternate and pinnate in arrangement; 

 leaves very small, narrowly linear, acute or acuminate, widest at base, de- 

 current, and mostly crowded ; midnerve slender but distinct. 



Locality: Fishing hut above Dutch Gap Canal ; very i-are. 



This plant is a good deal like S. snhuhta, but the leaves are proportion- 

 ally wider and not so falcate, while the ultimate branches are placed at 

 more uniform intervals. 



Sequoia, species ? 



Plate CXX, Fig. 9. 



Stem witli very broad elliptical to nearly circular leaf-scars, which 

 are spirally arranged. 



Locality: Found very rarely at Fredericksburg. 



This may possibly be one of the older twigs of S. Eeichenbachu 



' Flor. Foss. Arctica, vol. 3, pt. 2, p. 80. 



