The ultimate lobes are very generally falcate, especially the younger ones, 

 and are finely fringed on the rounded or outer edge. The spongy body of 

 the frond is composed of several strata of closely interwoven, anastomosing, 

 and subparallel longitudinal filaments, resembling those of a Callithamnion ; 

 the surface is coated with a pile of minute, simple or forked, incurved, su- 

 bulate, horizontally excurrent ramuli. Favella are clustered, surrounded by 

 an involucre of many ramuli, and scattered over the surface of the network, 

 on which they form little wart-like prominences. Tetraspores are plentifully 

 borne on the sides of the rarauli. The colour varies from a livid-purple to 

 a clear rosy-red, and fades through orange to yellowish and tawny. The 

 substance is membranous, but soft, holding water like a sponge. In drying 

 the plant adheres firmly to paper. 



A very curious Alga, with the structure and substance of a 

 sponge, and imbibing water and holding it as freely. By the 

 Tasmanian collectors it is called " the blafiket" a name aptly ex- 

 pressing its appearance when fresh, which is that of a piece of 

 flannel or napped cloth. Its external form is greatly varied. 

 Among the multitude of specimens before me there are scarcely 

 two which are moderately alike in ramification. All indeed are 

 formed on the same general plan, and, once seen, the plant is 

 readily, recognized under every form; but one is broad and 

 scarcely cleft ; another narrow, and cut up into innumerable 

 shreds ; and others, like the one selected for our figure, are mo- 

 derately lobed. 



This plant abounds in all parts of the western and southern 

 coast that I have visited. In Tasmania a variety occurs, in 

 the Tamar, a considerable way above Georgetown, and at first 

 looks like a different species, being thinner, and more purple 

 and fan-shaped than the ordinary state. On tracing it down the 

 river to the Heads of Port Dairy mple, it gradually blends into 

 the usual variety, nor is there any microscopic character to dis- 

 tinguish it. 



Fig. 1. Halopleoma Preissit; part of a frond, — the natural size. 3. Some 

 of the vertical, anastomosing, central filaments, and the horizontal, free, 

 superficial ramuli ; showing their connection. 3. Eamulus, with tetra- 

 spores. 4. A tetraspore. 5. An involucrated cluster of favellse. 6. A fa- 

 vella. 7. Spores: — the latter figures >«tfy»i/?ec?. 



