118 Blackman and Tansley . 
Sub-Family i. Dasycladem. 
Leaves branched dichotomously or polytomously, all with a 
specialised terminal or lateral, fertile portion. Incrustation absent. 
Genera. 
1. Dasycladus. Agardh, 1827. 
Stem bearing closely set whorls of about twelve leaves 
each. Leaves several times polytomously branched, 
each branch forming a closed segment. Fertile 
portion of the leaf a stalked spherical gametangium, 
terminal on the basal leaf segment, and producing 
isoplanogametes. Germination of zygote not observed. 
2. Chlorocladus. Sonder, 1871. 
Characters of Dasycladus , but the terminal branches of 
the upper leaves reduced to delicate hairs, and the 
contents of the fertile portion of the leaf dividing 
to form numerous aplanospores whose further develop¬ 
ment is unknown. 
3. Botryopliora. J. G. Agardh, 1887. 
Habit looser than in Dasycladus , vith stiffer dichotomous 
or trichotomous leaves, and lateral spherical fertile 
portions, two to four together at the bases of the leaf- 
brancnes, producing numerous aplanospores. 
Sub-Family 2. Cymopolieas. 
Characters of Dasycladeae, but leaf-segments of either the first or 
second order swollen so as to come into lateral contact and form a 
continuous cortex, which is incrusted with calcium carbonate. 
Genera. 
4. Neomeris. Lamouroux, 1816. 
Stem bearing closely set whorls of branched, mainly 
dichotomous leaves. Cortex formed by swelling of 
basal portions of branches of the second order. 
Branches of higher order hair-like, deciduous. 
Fertile portions of leaves spherical, terminal on basal 
segments, each producing a single aplanospore. 
5. Bornetella. Munier-Chalmas, 1877. 
Characters of Neomeris, but leaves polytomous, with fertile 
portions lateral, club-shaped, producing numerous 
spherical aplanospores. 
6. Cymopolia. Lamouroux, 1816. 
Thallus consisting of calcified segments separated by 
uncalcified constrictions. Stem repeatedly dichoto¬ 
mous in one plane, bearing closely-set whorls of 
polytomously-branched leaves, the terminal branches 
hair-like and deciduous. The persistent bases of the 
leaves consist at the constrictions of the thallus of the 
basal leaf-segments only, but on the calcified thallus- 
segments also of the swollen branches of the second 
order forming the strongly calcified cortex. Fertile 
pertions of the leaves as in Neomeris , 
