158 A COISTTBIBTITIOIS' TO, ETC. 



Islands the beach is lined for miles with entangled cables of this 

 plant much thicker than the human body. Hormosira BanJcsii 

 is a sea- weed which everyone must have noticed on the rocks near 

 high water mark, and it differs so .much from every other in its 

 leafless moniliform frond, that it cannot be mistaken for any other. 

 It derives its name from Jiormos a necklace, and sira a chain, as it 

 consists of a series of inflated intcrnodes, similar in character to 

 vesicles. There are many varieties of this plant, arising probably 

 from the depth of the water in which it grows, but Harvey refers 

 them to one species. The fructification consists of spore-cavities 

 sunk in the vesicated internodcs. Laminaria is so called from. 

 lamina, a thin plate, in allusion to the flat frond, and is popularly 

 termed " sea-girdle or tangle." L. dicjitata occurs in Europe as 

 well as on these coasts, and is one of those weeds which contribute 

 to the formation of kelp, and no sea- weed is said to be so rich in 

 iodine as the species in question. L. digitata and also L. potato - 

 rum are common, and the former extends some distance up the 

 Parramatta River. The other species derives its name from the 

 circumstance of its being used by the aboriginal natives for the 

 conveyance of water. Padina pavonia is a much smaller weed 

 than any of the preceding, and its general resemblance to the ex- 

 panded tail of a peacock has been noticed by all authors. The 

 frond is flat, ribless, fan-shaped, and marked at regular distances 

 with concentric lines. The genus Zonaria is represented by 

 several species, Z. Sinclarii being one of the most common. It is 

 called Zonaria from the Greek word, which signifies a zone or 

 girdle, because the frond, in many species, is marked with distant, 

 concentric lines. Padina and Zonoria, as well as Dictyota, which 

 is sometimes found in company with them, belong to the class of 

 sea-weeds called Dictyotecno, because when viewed under a lens the 

 fronds appear reticulated. 



Of the second series, or B-hodospermea?, which on account of 

 the brilliancy of their colours, and the elegance of their fronds, 

 are more especially objects of interest to the collector, there arc 

 numerous species on these coasts, but the genera most likely to 

 be met with without the trouble of dredging are Ptilota, Pltacelo- 

 carpus, and Plocamium. These, together with some of the more 

 minute species, which can scarcely be seen without the aid of a 

 microscope, arc often found at the roots of the brown sea- weeds, 



