linear, flat, midribbed leaflets ; the leaflets of each series being parallel to 

 each other, and those of each successive series issuing at right angles with 

 those of the preceding. The leaflets of the first series spring directly from 

 the primary branch (or marginal rib of the net), and each is continued into 

 an excurrent point, or tooth, on the outer or opposite side of the network ; 

 they stand from -|— ^ of au inch apart, and are slightly curved upwards. 

 The leaflets (or bars) of the second series rise, at intervals of ^V~To °f an 

 inch, from the upper side of the midrib of those of the first series, and each 

 anastomoses with the lower side of the midrib of the leaflet next above it ; 

 and those of the third series, in like manner, connect by a series of cross- 

 bars the leaflets of the second series. Those of the first and third series are 

 therefore parallel to each other, and those of the second are at right angles 

 to both. The interspaces between the crossbars form rectangles about thrice 

 as long as broad. Each network, when fully grown, is 10-12 inches long 

 and about an inch broad, and is elegantly recurved, like a scimitar; the 

 apex minutely hooked, and the outer margin ciliato-denticulate. The struc- 

 ture of the leaflets is uniformly cellular ; the surface-cells polygonal and 

 flattened. The substance is delicately membranaceous ; and the colour a 

 beautiful rose-red, becoming brighter in fresh-water. The cystocarps [cera- 

 midia) are formed in the midrib of metamorphosed primary or secondary 

 leaflets, and in either case the metamorphosed leaf is reduced to a winged, 

 clavate. mucronulate pedicel, near the summit of which the ceramidium is 

 formed : this is subglobose, inflated, with a minute obliquely-placed orifice ; 

 it has membranous walls, and contains, on a basal placenta, a dense tuft of 

 pedicellate, pyriform spores. The stichidia are formed out of the bars of 

 the second series in the network, and are elliptic or broadly lanceolate, con- 

 taining transverse rows of tetraspores. 



This, the most beautiful of all Algae, though known to bota- 

 nists for upwards of half a century, was scarcely to be found, 

 except in fragments, in any herbaria previous to the year 1844, 

 when Mr. Gunn discovered a copious habitat in Tasmania. 

 Peron's specimens probably came from Western Australia, where 

 this plant appears to be much rarer than in Tasmania. In the 

 latter island its habitat is in the deep and rapid estuary of the 

 Tamar, at a considerable distance above its mouth, and where 

 the water, though still very salt, is not so salt as on the open 

 coast. Hence probably arises the greater size and delicacy of 

 the Tasmanian specimens. 



A second and very distinct species of Claudea (C. Bennettiana, 

 Harv.) is found in the Paramatta River, Port Jackson, and a 

 third (C. multifida, H.), in Ceylon. 



Pig. 1. Claudea elegans; portion of the frond, — the natural size. 2. A 

 portion of a branch, bearing ceramidia, — not. size. 3. A metamorphosed 

 leaflet bearing a ceramidium. 4. Spores from the same. 5. A portion of 

 the network, bearing stichidia. 6. Stichidium, between sections of two bars. 

 7. Tetraspores : — the latter figures variously magnified. 



