98 Sturch . — Harvey ella mirabilis (Schmitz & Reinke). 
Harveyella , and as, so far as is at present known, its gonimo- 
blast is developed from an auxiliary cell formed before 
fertilization of the carpogonium, I think that the genus 
should be provisionally transferred to the Gigartinales, and 
placed near Harveyella . 
In both these genera, Choreocolax and Harveyella , the 
central portion of the thallus consists of a mass of cells more 
or less obviously arranged in filaments. Their thallus may 
be considered to be of the same type as those which possess 
a central strand of more or less interwoven branched filaments, 
but very much reduced owing to their parasitic habit. The 
following is suggested as a provisional classification of these 
two genera, the classification of the remainder of the Gigar- 
tinaceae being taken from the ‘ Pflanzenfamilien.’ 
Gigartinaceae. 
A. Thallus with a single articulated central 
axis. 
1. Endocladieae. 
4. Mychodeeae. 
B. Thallus with a median longitudinal strand 
of branched filaments. 
a . Strand obvious. 
2. Gigartineae* 
3. Tylocarpeae. 
4. Mychodeeae. 
5. Dicranemeae. 
6. Callymenieae. 
b. Strand much reduced. 
1. Cystocarp forming a fruit-cavity, in 
which are developed the spores. 
Cavity opens by an apical pore. 
7. Choreocolaceae. 
Parasitic thallus, with cells arranged 
in fairly distinct rows. 
19. Choreocolax . 
2. Gonimoblast branching freely among 
the thallus-cells beneath the peri- 
pheral layer. 
8. Harveyelleae. 
Parasitic thallus composed of sub- 
dichotomously branched filaments. 
20. Harveyella . 
