edge, with a rusty or buff-eoloured toraentum, composed of short, slender, 

 jointed hairs. Our specimens are not in fruit. The substance is leathery 

 and tough, retaining its toue;hness in drying. The colour in reflected light 

 is a dark brownish-red, but when viewed with transmitted light is a deep 

 blood-red. On exposure it fades through orange and yellow to dull greenish- 

 white. The plant does not adhere to paper in drying. 



The genus Peyssonnelia, founded on P. squamaria, a native of 

 the Mediterranean, is widely distributed, being represented not 

 only in all the warmer seas, but straggling northward along the 

 coasts of northern Europe. On the AustraHan shore there are 

 three or four species, of which the one now figured is the largest, 

 broadest, and least divided. I have little doubt but that my 

 plant is the same as Sonder's, though he describes his specimens 

 as being only " an inch long and broad, differing from P. squa- 

 maria by the undivided lamina and scattered fruit." To this 

 may be added that P. australis is much more brightly coloured 

 and more glossy. The concentric zoning is pretty evident on 

 my specimens, and I am not disposed to rely on this character 

 as distinguishing our plant from either P. major or P. squamaria. 

 If the three forms are to be retained as species, the present must 

 rest on its broad, nearly undivided, and bright-coloured frond. 



P. NovcB-HoUandics, Kiitz., has the bright colour of the present 

 species, but is divided into many narrow sublinear lobes. P. 

 multijida, Harv. (Alg. Exsic. 329), from Newcastle, New South 

 Wales, is still narrower and more divided, thick and rigid, and 

 of the dark-brown colour of P. squamaria. The fourth Australian 

 species (P. rubra, Grev.) is attached by its under surface, thin, 

 crustaceous and brittle when dry, covering stones in deep water : 

 it occurs both in Tasmania and in Port Jackson. 



Fig. 1. Peyssonnelia australis, — the natural size. 2. A vertical section, 

 showing the two strata of which the frond is composed, and some of the 

 fibres of the tomentum, — magnified. 



