456 102. ITOOPOBIACEJE. 



* Capsules not opening. — Leaves radical. 



1. IsoBTBS. Caps, in pouches formed of the swollen bases of 

 the leaves. Spores of two kinds attached to filiform 

 receptacles ; those of the outer leaves large, of the inner 

 very small. 



** Capsules bursting. — With leafy stems, 



2. Lycopodium. Caps, of one kind, 1-celled, containing 

 many minute spores. 



3. Sblaginblla. Caps, of two kinds, small containing many 

 minute spores, or larger and containing about 4 large spores. 



1. IsoETBs Linn. Quillwort. 



* No persistent leaf-bases. Caps, not wholly covered by the 

 membranous edge of the pouch. Back of swollen leaf-base 

 smooth. — Aquatic. 



1. I. lacuJtris (L.) ; 1. subulate roundish-quadrangular with 4 

 longitudinal jointed tubes upright dark green, larger spores 

 bluntly tubercled rather mealy, tubercles overtopped by the 

 valve-edges.— ^. 5. 1084. H. F. 55. iJ. vii. l.-Oorm with 

 longitudinal furrows. L. slender, broad and flat at the base, 

 but elsewhere between cylindrical and quadrangular, 2 — 6 in. 

 long. — Usually csespitose on the sandy and stony bottom of 

 lakes and pools in hilly districts. P. VI. E. S. I. 



2. I. echinos'pm'a (Dur. !) ; 1. subulate roundish-quadrangular 

 with 4 longitudinal jointed tubes patent pale green, larger spores 

 very acutely tubercled, tubercles overtopping the valve-edges. — • 

 /. of B. i. t. 1. — Much like Sp. 1. Corm not furrowed. L. 

 turning yellow, less rigid, flattened and dilated below. Spores 

 covered with long acute spine-like tubercles, not mealy. — 

 Usually solitary on the muddy bottom of pools and lakes in hilly 

 districts. Llanberis, N. Wales. Loch of Park near Aberdeen. 

 Ben Voirlich, Dumbartonshire. Gap of Dunloe, Kerry. P. VI. 



E. S. I. 



** Corm more or less covered by the persistent hardened leaf- 

 bases. Caps, wholly covered by the membranous edge 

 of the pouch. Swollen leaf-base with a central longitudinal 

 rugose band on the back. — Terrestrial. 



[J. Hys'trix (Dur. !) ; 1. filiform plane-convex obscurely tubu- 

 lar, persistent l.-bases short blackish each with 2 long horns and 

 an interm. tooth, larger spores white and bluntly tubercled. — 

 I. Duriei H. F. 56. — Corm small, rarely if ever quite naked. 

 L. very slender, ultimately very much enlarged at the base to 



