980 CRYPTOGAMIA. FILICES. Ophioglossum. 
ISOE'TES. Barr. FI. Anthers sessile within the base of a leaf. 
Fert. FI. Capsule two-celled, (one-celled: Hook., E.) 
within the base of a leaf. 
I. lacus'tris. Leaves awl-shaped, semi-cylindrical, bowed hack. 
{Hook. FI. Lond. 131—E. Bot. 1084. E.)— Bolt. 41— FI. Dan. 191— Dill. 
80. 2— Bay Ed. i. 2, atp. 1. 
Root fibrous ; fibres numerous, simple, slender, striking deep into the mud. 
Leaves growing in thick tufts, six or seven inches long, extremely like 
young rushes, convex on the back, flat, or slightly convex in front; at 
the base swelling into a kind of bulb, covered by a thin tender skin, 
which bursts and discovers numerous minute whitish seeds, which, ex¬ 
amined in the microscope, appear spherical, rough, somewhat transpa¬ 
rent, and having three ribs meeting in a centre. Woodw. Leaves so 
brittle that they break on the least attempt to bend them. The trans¬ 
verse diaphragms very visible. I have often found the plant in seed in July. 
Griffith. (The fronds themselves are highly curious. A tranverse sec¬ 
tion represents four tubes; a longitudinal one shows that these tubes are 
separated at regular distances by transverse bars or dissepiments, as in 
the tube of a Conferva. Hook. E.) 
Quill-wort. At the bottom of cold alpine lakes. In Ffynnon frech, a 
small lake near the top of Snowdon. Ray. Mr. Griffith. Near Llan- 
berris; and Llyn Ogwen, on Snowdon; Loch Tay, and other High¬ 
land lakes. Lyn y Cwn near Snowdon. Pennant. Derwent-water, Cum¬ 
berland. Mr. Woodward. (Ullswater, lower end; andGowbarrow-pike. 
Hutchinson. E.) Loch Lomond. Dr. Hope. (Loch of Clunie, Perth¬ 
shire, abundant. Mr. Brown. Loch Leven. Mr. Arnott. Lakes in 
the Rosses, Donegal. E. Murphy, Esq. In White Meer, near Ellesmere. 
Mr. Griffith. E.) P. May—Sept.*' 
Var. 2. Huds. Dill. 80. 1. 
Leaves not so stiff, from the base of which rises a stem throwing off shoots 
at different distances. Richardson, in R. Syn. 
I apprehend that Richardson here has applied the word stem, to the shoot 
which connects the offspring to the mother plant. 
I have found leaves of it in Llyn Ogwen, but could not procure an entire 
plant. Mr. Griffith. At the bottom of Derwent-water. Mr. Woodward. 
Var. 3. Huds. Leaves very brittle, sometimes twice as long as those of var. 
1, narrower and more pointed, transparent, with many minute pores, 
Richardson, in R. Syn. Grows with var. 1. ib. 307. 
FILICES. 
OPHIOGLOS , 'SUM.+ Capsules numerous, nearly globular, 
* (Fish are said to feed, and grow fat, on these plants. The taller, more slender varie¬ 
ties, have been suspected to be occasioned by the frequent rising of mountain waters; but, 
as the shorter kind is observed to be intermixed, in the same situations, and in an equal 
state of maturity, this suggestion is scarcely satisfactory. E.) 
t (From o<p*f, a serpent, and yhwaatx, a tongue ; a name exceedingly appropriate to the 
appearance of the plant. E.) 
