DESCRIPTION OF THE SPECIES. 315 



probcably dividing' higher up. The fragment on the left, partly covered by 

 tlie main leaf, appears to be a detached lobe, which is wrinkled from press- 

 ure. The plant on the whole seems to be nearer to Alalia than to any 

 other genus, but it is too poorly preserved to permit its character to be 

 definitely fixed. 



JUGLANDIPHYLLIBI, gen. nov. 



I place under this head a leaf that occurs rarely in the Potomac flora. 

 Its affinities are doubtful, but it seems to be nearer to Jiu/lam than to any 

 other g'enus. The specific description gives the generic description also. 



JUGLANDIPHYLLUM INTEGRIFOLIUM, sp. nOV. 

 Plate CLVII, Figs. 3, 5, 6. 



Leaves of medium size, bases not seen, tips oval in outline, prolonged 

 into a tooth-like tip that is turned to one side; leaf-substance thin ; mid- 

 nerve strong ; jirimary lateral nerves strong' and very distinct, going' off at 

 regular and equal distances alternately, parallel, arching forward to near 

 the margin, where they are bent abruptly upwards, gradually approaching 

 the margin, branches going off at a large angle from these and the mid- 

 nerve and forking, making by their meeting a set of strong meshes, that are 

 elongate, subrhombic, varj-ing much in shape and size, and standing mostly 

 at right angles to the main nerves with their longer dimensions ; these 

 meshes having sharp angles and very distinct ; the ultimate reticulation 

 (Fig. 6") strong, being made by nerves which meet nearly at a right angle, 

 the meshes four to six sided and rotundate. 



Localities : Deep Bottom, comparatively common ; White House 

 Bluff; very rare. 



This plant has some of the features of Persca, and in some respects it 

 resembles some forms of Qucrcus. 



MYRIC^PHYLLUM, gen. nov. 



This genus includes plants that stand nearer to 3fi/rica than to any 

 other, yet are not near enough to be placed in that genus. Generic de- 

 scription same as the specific description given below. 



