114 THE MEDALS OF CREATION. Crap. VI. 
by its slender and minutely divided wedge-shaped leaflets. _ 
The Sphenopteris Mantelli did not attain a considerable | 
size ; the largest stem I have seen indicated a plant of five 
or six feet in height. This Sphenopteris is sometimes asso- 
ciated with the remains of a beautiful plant of the genus 
Alethopteris,* the leaflets of which, in some examples, bear 
the fructification. (Wond. p. 394, Lign. 89.) 
cy) 
\\\II 
Lien. 21. CYCLOPTERIS TRICHOMANOIDES; a single leaflet; nat. 
Oolite, near Scarborough. 
Cyciopreris (rownd-leaf). Lign. 21.—The frond is 
simple and entire, or but slightly lobed at the margin, and — 
generally orbicular, or kidney-shaped: there is no midrib ; — 
the veins are numerous, equal, and dichotomous, or forked, 
and radiate from the base. The form and disposition of the 
veins resemble those of some living species of fern ; the — 
absence of a median rib, or vein, is the most striking 
* Alethopteris elegans of Dr. Dunker. Mon. Nord-Deutschen Weald. 
pl. vii. fig. 7. 
