324 THE rOTOMAC OR YOUNGER MESOZOIO FLORA. 



HEDERiEPHYLLUM CRENULATUM, sp. nOV. 

 Plate CLXII, Fig. 3. 



Leaf rather small, probably rotundate, with subcordate base, shape 

 not fully shown; margins undulate to crenate ; leaf-substance thick; petiole 

 and lower portion of the midrib comparatively strong; midnerve rapidly 

 diminishing above ; primary nerves radiating from the top of the petiole, 

 the middle one the strongest ; on each side of the midnerve, at its base, a 

 strong lateral nerve goes off and proceeds obliquely upwards to near the 

 margin ; this sends off from its base a strong, much divided branch, which 

 turns outwards and downwards ; both this and the main lateral nerve from 

 which it proceeds forked often, the branches flabellately diverging ; reticu- 

 lation not seen. 



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



This plant is a good deal like some forms of PopulophyUum, but the 

 nervation, although different in some details from the species next to be 

 described, is essentially the same. In this the branches go off much more 

 obliquely, and the basal outermost branch is proportionally much larger. 

 The leaf is much like some of those of Hedera Helix. 



Heder^phyllum angulatum, sp. nov. 



Plate CLXII, Fig. 1. 



Leaf-substance thick and glossy; leaf small, with m.argins straight, 

 and at intervals bending abruptly, forming right angles or larger angles 

 with the former direction, the lower margin nearly at right angles with the 

 petiole and turning slightly downwards ; shape of the lower part of the 

 leaf polygonal ; terminal lobe incomplete, so that its shape can not be made 

 out ; on each side of it a broad tooth or lobe like the lateral one of Lirio- 

 dendron occurs, separated from the terminal one by a broad sinus, so that 

 the upper margin of the lateral lobe has a direction nearly at right angles 

 with the midrib ; petiole long, rather slender, but distinct ; primary nerves 

 radiating from the top of the petiole at the base of the leaf, in type similar to 

 that of AralicephyUum. There are three primaries ; the middle and principal 

 one proceeds to the tip of the leaf, and the two lateral ones to the lateral 



