the Colony of Western Australia. 531 



of tlie reef, and afford well-slieltered nooks for a variety of beautiful Algfs. Tlie 

 water in these basins is always intensely transparent; the bottom frequently of 

 white sand; and the steep and craggy sides clothed with Algie vegetation, in 

 which the brightest tints of green, purple, carmine, and olive, and the most grace- 

 ful waving forms, are mingled in rich variety. Ilere is the favourite locality of 

 some eight or ten species of Caulerpa, of several very distinct forms, and every 

 one a beautiful object. All these are green ; but the tints vary from the darkest 

 bottle-green to the pale, fresh green of an opening beech leaf. Some resemble 

 soft ostrich feathers ; others, branches of the Norfolk Island pine ; others, strings 

 of beads; others, squirrels' or cats' tails; and C. scaljxlliformis is like a double 

 saw. Under the shelter of the Caiderpce the smaller Bhodosperms (such as 

 Dasyw and Callithamnia) are often found. But these are most numerous on 

 the perpendicular sides of the border reefs, where also rich meadows of Cau- 

 lerpce are seen waving in the clear water, from a foot beneath the surface to a 

 considerable depth. Various Fucoidece and EcUonia radiata are scattered here 

 and there through the deeper pools, and on the sides of the reef None of these 

 are ever left dry at low water. In many places a profusion of a Bryopsis {B. 

 Australis) enlivens the rocks with its silky tufts of green, each tuft separate 

 from its neighbour. Some of the shallower reefs, near high-water mark, are 

 partially covered with sand: and this is the habitat oiPeniciUus arbitscida, a little 

 green Alga, which may be compared either to a miniature tree, or to a shaving- 

 brush. Struvea plumosa abounds on all the reefs, at about half tide level, ge- 

 nerally growing on the very edges of the rock-pools and border-reefs. I obtained 

 from Mr. Sanford, Colonial Secretary, a specimen of a new Struvea, sent by 

 Mrs. Drummond from Champion Bay, differing from S. plumosa in its vastly 

 larger size, and more compound network. The specimen has been bleached 

 white, and in this state strongly resembles a beautiful pattern of old j^oint-lace, 

 and might be made into ladies' collars, as it is of a tough substance. 



I shall conclude this summary with a few remarks on the geographical dis- 

 tribution of the species collected. 



The annexed descriptive catalogue contains 352 species: of which 277 are 

 (so far as we yet know) peculiar to the Australasian Flora, and 75 belong 

 either to pelagic species, or to more or less distant botanical regions. They 

 are grouped as follows: — 



VOL. XXII. 3 z 



