318 THE POTOMAC OK YOUNGER MESOZOTC FLOEA. 



PI. CLXIII, Fig. 1 , differs in several jjoints from PI. CLXIV, Fig. 3, 

 being more like Ar. acutilobum. 



Arali^phyllum acutilobum, sp. nov. 



Plate CLXIII, Fig. 2. 



Leaves small, broad fan-shaped, rounded off rapidly at base ; leaf-sub- 

 stance thick ; primary nerves comparatively strong and distinct, the middle 

 one the strongest, three in number, radiating from the base of the leaf; 

 leaves cut into three principal lobes ; the middle lobe narrowed at the base, 

 flared out in the middle, and nari"owed again towards the tip so as to be 

 broadly elliptical in outline, considerably larger than the lateral ones, sep- 

 arated from the latter by a sinus that is directed outwards and widest at the 

 base; main lateral lobes turned at first outwards and then curved slightly 

 upwards, inequilateral, witli a very convex outer margin furnished with a 

 short acute tip, almost mucronate ; these main lateral lobes towards the Ijase 

 of the leaf incised into an ovate, subacute, short lobe that is turned out- 

 wards and slightly downwards ; the outer primary nerves, near their base, 

 send off a strong branch on the lower side that goes into the outermost 

 small lobe or tooth; reticulation not seen. 



Locality: 72d mile-post, near Brooke; very rare. 



This plant is a good deal like the preceding species, but seems to be 

 distinct i"rom it. 



Arali/EPhyllum magnifolium, sp. nov. 



Plate CLIX, Figs. 9, 10. 



Leaf very large, but the specimens found are too fragmentary to make 

 out the shape ; nerves seen, especially the primaries, very strong : the 

 primaries, three in number, i-adiating from the same point at the base of the 

 leaf, the middle one being the strongest ; the lateral or outermost primaries 

 send off some distance above their base a strong nerve on the lower side ; 

 the branches sent off by them higher are not so strong; the arrangement 

 of these principal nerves indicates that the lobing of the leaf is similar to 

 thnt of tlie preceding species. 



