158 THE POTOMAO OR YOUNGEE MESOZOIC FLORA. 



much attenuated towards the summit, alternate to subopposite, and termi- 

 nating in a slender toothed or lobed segment ; pinnules small, separate in 

 the lower part of the ultimate pinnjB, but united at base in the upper part 

 of the same, attached by a base slightly narrowed and decurrent, cut away 

 obliquely on the upper side of the base, inclined forwards, alternate to 

 opposite. Towards the summit of the ultimate pinnaj the pinnules diminish 

 in size and in the number and depth of the teeth, the uppermost ones 

 being entire and elongate-oblong in shape. The lower and middle pinnules 

 of the ultimate pinnai are generally subrhombic in form and vary somewhat 

 in the number and form of the teeth; they terminate in a comparatively large 

 triangulai- or ovate tooth or lobe, which is generally entire and rarely 

 slightly dentate, and generally show two more or less acute teeth on each 

 side and in pairs, a pair near the base and one near the summit, the mem-^ 

 bers of the pairs being opposite or subopposite. Sometimes additional teeth 

 appear, generally on the posterior margin of the pinnules; principal nerves 

 several, departing separately from the rachis of the ultimate pinnae so as to 

 fill the central jwrtion of the base of the pinnules. The outermost ones fork 

 once and curve outwards, the inner ones fork sevei-al times and diverge 

 slightly in a flabellate manner; the ultimate branches are short and divero-e 

 strongl)^ ; all the nerves strong. 



Locality: Fredericksburg ; rare. 



This plant is in many features like Ctenoptcris ins'ujnis. It differs from 

 this mainh^ in the small size of the pinnules, the greater variability of tlie 

 teeth, and in the character of the ultimate forking of the nerves. In C. 

 insignis the ultimate branches of the nerves are long, slender, and nearly 

 parallel. Perhaps this is merely a small variety of that plant. 



Ctenopteeis integkifolia, sp. nov. 



Plate LXII, Fig. 2 ; PUito LXV, Fig. :5. 



Frond unknown ; pinnules oblong to subelliptical, slightly curved for- 

 wards, subacute, obliquely cut away on the anterior margin at base, 

 decurrent on the lower side, separate to the base in the lower portions of 

 the ultimate pinnae, united slightly in the upper ones, which are much 

 diminished in size ; nerves several and distinct, departing from the rachis 



