238 
THE SEAWEEDS 
marginal rib, and from the concave side spring at intervals similar curved 
branches or leaflets bearing a network on the convex side. These again may 
give off similar secondary leaflets. The framework of the network consists 
of firm parallel ribs which pass at right angles to the marginal rib to project 
beyond the free margin of the network, something like the teeth of a fine 
comb or the vanes of a feather. These ribs are joined by short slender bars 
running at right angles to the ribs, from each to the next. These secondary 
bars are united similarly by a third series at right angles to the secondary 
and parallel to the primary ribs. 
The cystocarps are formed from the cross bars of the first or second order, 
which become transformed into a winged, clavate, mucronate pedicel, the 
cystocarp being formed near the summit. The stiehidia are formed out of 
the secondary bars, and are elliptical, containing transverse rows of tetra- 
sporangia. Colour dull-red when growing, becoming rose-coloured on dry- 
ing. Substance firm, somewhat cartilaginous. 
Claudea elegans has been dredged in 5 fathoms to 10 fathoms of water at 
Fremantle, in Western Port, and the Tamar estuary. Svedelius records it, 
together with other typical Australian algae, from the North Arabian Sea, 
off the coast of India. Truly a remarkable distribution. 
BONNEMAISONIACEAE (Trev.) Sohn. 
Erect plants with decompound branched axis, growing in one plane, 
branches often pectinate with ramuli. 
SYNOPSIS OF THE GENERA. 
A. — Apical cell transversely articulate. Frond flat 
or two-edged, with midrib and opposite trans- 
verse nerves from midrib to margin 
B. — Apical cell obliquely distiehously articulate. 
No transverse nerves. 
1. Frond flat, midribbed. Cystocarps globose, 
stipitate, borne on the margin of the 
frond 
2. Frond narrow, two-edged, midribbed below 
alternately pectinate-serrate. Central 
tube in the axis. Cystocarps ovoid, 
sessile, lying obliquely on the upper face 
of the segment near the apex 
3. Frond filiform, not compressed. Central 
tube in the axis. Oppositely ciliate- 
plumose. Cystocarps stipitate, replacing 
simple pinnules 
Leptopliyllis 
J. Agardh. 
Ptilonia 
J. Agardh. 
Deli sea 
Lamouroux. 
Bon nemaisonia 
C. Agardh. 
