CXLV. LYCOPODIACER. 671 
Minute plant with radical linear leaves surrounding a leaf- 
ess peduncle, Spore-cases all similar, solitary within 
the bracts of a eres spike . 2. PRYLLOGLOSSUM. 
Stems branch mall leaves “usually crowded in 4 
^ eie sony v within the nica of ter- 
minal spikes or the upper leaves of the st 
Spore-cases and spores all simi 3. LYCOPODIUM. 
8 cases and spores of two inds. "Plants usually 
weaker or smaller than in Peres A 4, SELAGINELLA. 
Small floating plant with small crowded leaves. Spere- 
rae at 2 kinds in the axils of some of the stem- 
5. AZOLLA, 
i Toafy or with distant scales, „ Spore- -cases 2 or 
together, united into a 2- or 3- -celled A or ae 
Stems simple, leafy. Sori cas odlet "3 . . 6. TMESIPTERIS. 
Stems dichotomous, with min viuo scales. Sori 
usually 3-celled. ids. . .. T. Psmorum. 
1. ISOETES, Linn. 
Aquatie plants entirely submerged or rarely terrestrial in swampy 
or wet sandy places. Leaves linear and thick or subulate, crowded on 
a short thick rhizome, dilated and concave at the base, the margins of 
the cavity often more or less folded over the spore-cases. Spore-cases 
sessile at the base of the leaves, solitary, membranous, of two kinds, 
ose of the outer leaves filled with spherical macrospores, marked 
with a transverse raised line, and above it 3 radi 
lines, those of the inner leaves filled with minute powdery micro- 
spores. 
A small genus having nearly the general range o of the order Mee in hot or dry 
sace It has been very carefully studied especially by Duri Y and Alex. Braun, 
W. D 
read 
antage of examining F. Mueller's 
w rs belie 
I. lacustris. I bam fort P i ge had the adv 
own 1 vo un : uns fen ther with "the Marsileacez were 
"t 
wn collections, as the p arcel — = em toge 
accidently omitted to be sent to m. 
Subm hick leaves from 2 to above 
erged cw with rather thick leave D sels 
T 1 £110 
errestrial ‘or swampy plant with filiform ` eaves o . 2. I. Drummondii. 
I aiaia seen I. Muelleri, A. Br. in Berl. Monatsber. 1868, A ven 
hampton, ga na and am unable to y os any opinion as to how far it differs from. 
either of the above 
1. I. lacustris, Linn.; Hook. Brit. Ferns. t. 55.—A perennial of 
a bright green, form Se ors tufts under the water. Leaves 
rather thick, linear, usual] to 3 in. lon on 
T9 ove 6 in. ee water, their enlarged bases giving 
the plant 3 s the old 1 ually decaying 
e plant a slightly bulbous aspect, eaves us 
entirely lihoai dtes the scale-like remains characteristic of 
