110 
the first or central, the sporangia the lateral cells. This rule seems 
also to be observed in the fundus of the verticil, in which we find the 
antheridium on the inner aspect of the basal node, while the spor- 
angia are lateral or even external, and, in other cases, these basal 
cells produce adventitious leaflets instead of sporangia, carrying out 
the same plan found on the leaf-node. The coronula is persistent or 
evanescent.* The leaves which bear fruit become compacted into 
more or less dense heads (or "nests "), owing, apparently, to a dimin- 
ished growth of stem and leaf ; the verticils are approximate, often 
closely so, and the leaves are incurved, forming a tangled mass. 
The following key has been arranged to include the species known 
at this time. 
KEY TO THE SPECIES OF TOLYPELLA. 
I. Obtusifolia. — Coronula evanescent. Sterile leaves undivided, 
A, Ultimate cell of the primary ray of the leaf longer than 
the other cells. T. lon^icovia^ A.Br. 
B. Ultimate cell not longer. 
f Leaflets attenuate. 
/ 
2. Marine. Nucleus 370-500/f long. T. nidifica, Leonh. 
(Europe.) 
3. Submarine. Nucleus 300-340/^ long. T. Normaniana, 
Ndst. (Europe.) 
X Leaflets not attenuate. 
4. Saline. Nucleus 300-360// long. T.glomerata^ Leonh. 
5. Fresh water. Nucleus 425-475// long, maturing in fall. 
T. comosUy Allen. 
IL AcuTiFOLiA. — Coronula persistent,^ 
A. Indivisa, Sterile leaves undivided- 
6. Nucleus 350-375/1 long, leiopyrena. T.proli/era,l.^on\\. 
7. Nucleus 425-450// long, oxygyra. T. fimbriata, Allen. 
B. Divisa. Sterile leaves divided (usually into four terminal 
leaflets.) 
t Attenuaia, Leaflets attenuate. 
Secondary ray undivided, sterile. 
8. Nucleus 285-355/i, rays 4-7-celled. T.Calif ornica, A.Br, 
9. Nucleus 330-340//, rays 3-4-celled, T, stipitata, Allen. 
Secondary rays divided, fertile. 
10, Nucleus 360-425// long. T, intricata, Leonh. 
11, Nucleus 450-500// long. T. intertexta, Allen- 
tf Non attenuata. 
12, Ultimate cell mucroniform; nucleus 480-500//. T.apic- 
ulata, A.Br. (S.Am.) 
T. lofigicoma, A.Br. (MS., 1855). — The following account of this 
species is taken from " Braun's Fragmente, by Nordstedt." 
''T. longicoma is related to T. nidifica and glomerata from which it 
* It seems persistent in all the species having acute leaves and evanescent in all 
the species with obtuse ones. 
f In number 11 the coronula is sub-persistent only. 
