370 
THE SEAWEEDS 
Ceramium clavuiatum Agardh. 
= Centroceras clavuiatum Montagne. 
Frond 10 cm. to 17 cm. long, filiform, spinose, regularly dichotomous, 
fastigiate, proliferous from the axils ; terminal segments incurved and for- 
cipate, the lower articulations longer than wide, the spinules of the nodes 
verticillate. Tetrasporangia verticillate round the nodes. Cystocarps in 
pairs, the ramelli of the involucre four to five, rising above the fruit. 
West, South, and East Australia. 
Ceramium cinnabarinum (Gratel.) Ilauck. 
= C&ntrocerus cinnabarinum J. Agardh. 
Frond 5 cm. to 12 cm. long, filiform, not spinose, dichotomous, fastigiate, 
sparsely proliferous, terminal segments subforcipate, erect, lanceolate, con- 
spicuously attenuated; the zones of the nodes protracted into minute 
apices at the upper edge ; cortical cells arranged longitudinally, alternately 
transverse, almost wider than long. Tetrasporangia almost’ immersed, 
prominent. Colour purplish; adheres to paper. 
South Coast of Australia, New Zealand, Cosmopolitan. 
The following genus is placed in the Ceramiaceae by De Toni, but is of 
uncertain position. 
THAMNOCARPUS Harvey. 
Frond filiform, branched, articulated, monosiphonous, the stem and 
branches (in many species) at length thickened internally or coated 
externally with decurrent filaments; ramuli always pellucidly articulate 
and monosiphonous. Cystocarps generally in pairs, axillary or sessile on 
the branches, naked, containing numerous angular spores. Tetrasporangia 
naked, sessile or pedicellate on the ramuli. 
Thamnocarpus Gunnianus Harvey. 
Frond 15 cm. to 25 cm. long, bushy, cartilaginous-corneous, terete, widely 
branched, the upper ramuli very dense, subfastigiate, obtuse ; on the fertile 
ramuli sparse fascicles of filaments are arranged at the apices ; articulations 
of the filaments about twice as long as wide. 
South Australia, West Australia, Tasmania. 
Thamnocarpus penicillatus (Harv.) J. Agardh. 
= Callithamnion penicillatum Harvey. 
Tree-like; stem and branches thickly corticated throughout, decom- 
poundly branched, ultra-setaceous ; branches nearly naked, or thinly beset 
with minute, byssoid, pencil-like articulated ramuli; ramuli clothed with 
very slender, many times forked ramelli. 
Attachment or holdfast a minute disc. Frond 5 cm. to 8 cm. high, about 
1 mm. thick at the base, gradually tapering upwards, irregularly branched, 
inarticulate, opaque, thickly coated with cortical cellules. Branches virgate, 
alternate, acute, older ones nearly naked, younger ones emitting minute 
ramuli. Ramuli 2 mm. long, slender, articulate, clothed with minute soft, 
forked ramelli. Colour of stem dark-red, of the ramuli rosy. 
Victoria (Port Phillip — on Macrocystis ) . 
