§ 22r 



CLATHRARIA LYELL1I. 



397 



whence the name, Clathraria, is derived : but the upper 

 10| inches is covered by the petioles, some of which are 

 abortive, being entire and rounded above ; while others 



Lign. 91. — Summit of a stem of Clathraria Lyellii; 



From the Chalk-marl at Bonchurch, Isle of Wight; discovered by 

 Captain Ibbetson. 



This fossil is the summit of a stem garnished with petioles or leaf-stalks on the 

 upper part : from the lower portion the petioles have been removed. The internal 

 axis is seen at a. The original is fifteen inches in length ; and eleven and a half in 

 the widest transverse diameter. It is deposited in the collection of the Isle of 

 Wight Fossils, in the Polytechnic Institution, London. 



have their summits marked with vascular pits, disposed 

 with great regularity, as shown in Lign. 92, c ; these indi- 

 cate the former attachment of leaves, that were shed 



