DESCRIPTION OF THE SPECIES. 259 



leaves, so far as seen, inserted only laterally, strongly decurrent, and 

 adnate or united, thick and leathery, strongly recurved, oblong to ovate, 

 acute or acuminate, much wider at base than elsewhere, cut away on the 

 upper side; midnerve very strong and rigid. 



Localities: Fishing hut above Dutch Gap Canal; hill-side near Poto- 

 mac Run; near Telegraph Station; rare at each locality. 



This well-marked plant is in some respects like some of the species 

 of rafjiophylliim (Pachyphyllum). The shape and the great thickness of 

 the leaves are the main points of resemblance. The fine specimen given 

 in PI. CXXVII, Fig. 2, sliows towards the tips of the ultimate twigs a 

 recurvation stronger than usual, so that the leaves stand nearly at right 

 angles to the stem. The plant belongs to the type of Sequoia Couttske. 



Sphenolepidium pachyphyllum, sp. nov. 



Plate CXXXI. Figs. 6, 7. 



Branches long, rigid, and slender, sending off at irregular intervals 

 alternate subordinate twigs ; leaves, so far as seen, strictly distichous, with 

 no facial ones, crowded, adnate at base or overlajiping, mucli wider at 

 base than elsewhere, gradually tapering to an acute tip so as to give them 

 a triangular or ovate form ; acute or acuminate, straight or slightly falcate, 

 attached nearly at right angles to the stems, very thick and dense in 

 texture, with an unusually large midnerve. 



Locality: Near Telegraph Station. 



This strongly marked plant is very rare. It is very much like I'af/io- 

 l)hyUum Heer [ParJi/jphij/lniii Saporta), in the great thickness of the leaves. 

 It is almost exactly like the form of Sequoia Reichcnhnrhi given by Scheidv.' 



Sphenolepidium Virginicum, sp. nov. 



Plate CXXV, Fig. 4 ; Plate CLXVI, Fig. C. 



Branches comparatively stout, alternate ; facial leaves elliptical and 

 close appressed, lateral ones ovate, acute, slightly divergent and incurved 

 at the tips, strongly decurrent, all with distinct midnerves, on the youngest 

 twigs they are elliptical and closely appressed ; female strobile terminal on 



■Foss. Pll. (ler Wenisdorfer Schichteii, PI. 4, Fig. 2. 



