OF SOUTH AUSTRALIA. 
349 
Subfamily Crouanieae Schmitz. 
CONSPECTUS OF THE GENERA. 
I. — Fronds slender, filamentous, principal filaments confervoid in a 
single series of cells. 
Ballia Harvey. Cystocarps in axils of short branches. 
Antithamni&n Naegeli. Cystocarps terminal. 
II. — Fronds terete, central axis bare or corticated with rhizoids. Ramelli 
short, passing out from axis, cohering together with mucous. 
Crouama J. Agardh. Central axis bare or moderately corticated. 
Short verticillate ramuli from axis growing out separately or 
together. 
Lasiothalia Harvey. Central axis soon densely covered with rhizoids 
and then inconspicuous. Fronds pilose, piles emerging from a 
mucous stratum. 
III. — Fronds thick, complanate, central axis densely corticated. 
Gattya Harvey. Cortical stratum of cells constantly monostromatic. 
Ptilocladia Sonder. External cortical stratum densely cellular in anti- 
clinal series, internal lax. 
BALLIA Harvey. 
Frond filiform, rigid, dendroid; the stem and branches covered with a 
plexus of hair-like, short fibres ; ramuli pellucidly articulate, pinnately 
decompound. Involucrate favellae terminating short pinnae and contain- 
ing numerous angular spores. Tetrasporangia born on the hair-like fibres 
of the stem and branches. 
Ballia Robertiana Harvey. 
Attachment an expanded disc. Fronds tufted, 6 cm. to 15 ,cm. long, 
distichous, decompound-pinnate, the main branches and lesser divisions 
opposite, patent, subdistant. Stem and branches densely clothed with 
short, rigid, hair-like filaments, w^hich throw out rhizoids that are woven 
round the branches in an inextricable plexus. The ends of the branches 
are pellucidly articulate, the articulations cylindrical, not .contracted at the 
joints or obovate (as in B. callitricha ) , and are distichously plumulate 
throughout. The articulations of the rachis are cylindrical ; its ovate pinnae 
are so closely pinnulated that the parallel pinnules touch each other through 
almost their whole length, and the pinna looks like a leaflet. Tetra- 
sporangia are borne on the stupose fibres of stem and branches. Favellae 
surrounded by numerous inrolled, elongate, branched involucral ramuli, 
borne on shortened branches. Colour dark brownish-red. Substance rigid. 
Plant adheres to paper scarcely at all. 
South Australia (Eastern Bays), Victoria (Port Fairy), Tasmania. 
