268 



Scientific Proceedings, Royal Dublin Society. 



Dermal Appendages. 



The dermal appendage, which is a scale, is shown in Fig. 12. It is a 

 thin-walled scale, and the tip of it breaks up into a number of small hairs. 



Fig. 12. — Hymenolepis spicata. Scale from rhizome. 



It is attached to the epidermis at about one-third its length from the 

 broader end. 



Anatomy. 



The stelar anatomy of Hymenolepis shows the same perforated 

 dictyostelic structure as Paltonium and Drymoglossum, except that in 

 Hymenolepis the leaf-traces come off closer together owing to the crowding 



Fig. 13. — Hymenolepis spicuta. Diagrammatic drawings of stele. 



of the leaves. Fig. 13 illustrates the stele of H. spicata. There are normally 

 five meristeles (1), and the root-traces arise externally from the centre of 



