346 
THE SEAWEEDS 
in a hyaline periderm. Colour red. Substance cartilaginous, much firmer 
than others of the genus. Adheres to paper. 
West Australia (King George Sound). 
Muellerena (?) insignis (Harv.) De Toni. 
= Crouania insignis Harvey. 
Frond 20 cm. to 30 cm. long or more, attenuated above, pyramidal, 
irregularly branched, ramuli patent, verticillate at the joints, below ver- 
rucose, with prominent rings of nodes, apices spongiose, almost confluent, 
ramelli verticillate, the inner ones curving from whorl to whorl and covering 
every part of the frond, forming an intricate corticate tube like a net; 
the outer ramelli are free, rigid, conspicuously attenuated towards the 
apices. Articulate. Substance rather cartilaginous. Colour purple-brown. 
South Coast of Australia, Tasmania. 
PSILOTHALLIA Schmitz. 
Fronds erect, plane and almost two edged, soft, alternate, distichous, 
shortly pinnulate ; central tube articulate (apical cell transversely divided) 
ramelli filiform disposed in four or five verticils; cortex dense, completely 
surrounding central axis. Tetrasporangia situated on short, lateral, upper 
ramuli, on the ends of monosiphonous, subdivided ramelli. Cystoearps as 
in Dasyphila, on heteromorphic pectinate ramelli. 
Psilothallia striata (Harv.) Schmitz. 
= Ptilota striata Harvey. 
Frond slender, two-edged, alternately decompound; branches and their 
divisions subclistant, rod-like, transversely rugulose, closely pectinato- 
pinnate; pinnules alternate, subulate, inarticulate, transversely striate. 
Attachment or holdfast, a large flattened disc. Fronds tufted or solitary, 
15 cm. to 30 cm. long, compressed and sharply two-edged, alternately and 
irregularly branched. Branches three or four times decompound, divisions, 
erecto-patent, issuing at acute angles of unequal length. All branches 
closely pinnulated with minute alternate pinnules, 2 mm. to 4 mm. long. 
The favellae are very minute, sessile near the tips of the pinnules and 
surrounded by confervoid, articulated, strongly involute filaments. The 
tetrasporangia are borne on the ends of the branches of minute confervoid 
filaments, which issue from either edge of the pinnules. Colour dark-red. 
Substance cartilaginous. Adheres imperfectly to paper when dry. 
West Australia (Rottnest Island). 
Psilothallia (?) siliculosa (Harv.) Schmitz. 
= Ptilota siliculosa Harvey. 
Frond irregularly pinnate, pinnae alternate on the ancipitous rachis, 
which is prominent and ribbed ; pinnellae corticate to the apices, acuminate, 
close together, entire. Tetrasporangia carried in irregular rows on the 
upper margin of the pinnellae, short and almost spongiose ; minute incurved 
articulate filaments rise from the surface enclosing tetraspores singly at 
the base with their incurved apices. Cystoearps are found singly at the 
inner margin, below the apices, sessile, globose. 
West Australia (Rottnest Island). 
