174 THE POTOMAC OR YOUNGER MESOZOIC FLORA. 



ENCEPHALARTOPSIS, gen. nov. 



Leaves pinnate, leaflets oblong, linear-elliptical, obtuse, terminat>ed by 

 several spinous teeth, margins having irregularly placed, shallow, spinous 

 teeth ; nerves numerous, closely placed, forking one- or more times and at 

 varying intervals, slightly diverging, and mostly ending in the teeth, anas- 

 tomosing occasionally by branches sent off abruptly from one nerve to 

 another. 



This curious genus has been found as yet with only one species. It 

 combines the features of Enceplmlartos with the anastomosing nerves of 

 Ctenis. It is so close to Encephdartos tliat, were it not for the occasional 

 anastomosis of the nerves, one would have no hesitation in placing it in 

 that genus. It probably should be regarded as the prototype of that 

 genus. 



Encephalartopsis nervosa, sp. nov. 



Plate LXX, Fig. 4 ; Plate LXXI, Figs. 3, 4 ; Plate LXXII, Pigs. 3, 4. 



Leaves and leaflets with the character given for the genus ; the shal- 

 low, spinous teeth on the margins vary in shape, and tend to pass to rec- 

 tangular notches ; the teeth do not appear on the basal portions of the leaf- 

 lets ; the base or attachment of the leaflets was not seen ; the nerves are 

 numerous, closely placed, fine but distinct ; they slightly diverge, fork at 

 long intervals and at varying heights throughout the length of the leaf, and 

 are approximately parallel; they anastomose rarely by abruptly sending 

 off branches to unite with the adjacent nerve; the anastomosing branches 

 make comparatively large angles with the parent nerve. 



Locality: Fredericksburg; rare. 



This plant evidently varied a good deal in the size of its leaves, for 

 the fragment PI. LXXII, Fig. 4, is much larger than that given in PI. 

 LXX, Fig. 4. In PI. LXXI, Fig. 3, the position of the two leaflets indi- 

 cates that they were disposed in a pinnate mannei". 



CTENOPHYLLUM, Schimper. 



Leaflets variable in size, mostly small, long, linear, comparatively 

 narrow and ribbon-shaped, gradually nan-owed towards the ends, attached 



