112 



The Irish Naturalist. 



[May, 



The two remaining British Ferns belong to the Ophioglos- 

 sacecT, an aberrant group with affinities towards the Club- 

 mosses. The stem is very short, subterranean, perennial, and 

 sends up annually a green leafy frond, from the stalk of 

 w^hich springs an erect branch which bears the fructification. 

 In weakly plants, or in situations that are too much shaded, 

 the fertile branch is not produced. In the well-known Adder's- 

 tongue, Ophioglossum vulgatiun, the barren branch of the 

 frond is undivided and egg-shaped in outline ; the fertile 

 branch is very narrow, and bears two rows of spore-cases 



^ig4. 



I^ig3- 



Fig 2. 



Ophioglossum vutgatiim. Shane's Castle, Co. Antrim, 



R. Ivl. P., 1S91. 



stmk in the tissue in its upper portion. Abnormalities afe 

 rare, but I once came across a field full of abnormal forms at 

 Shane's Castle, Co. Antrim. Three of the most interesting 



