k line in diameter, hard and rigid, solid, smooth or set with rough points, 

 dichotomous or vaguely branched, the lower portions more or less naked. 

 Brandies simple, 2-4 inches long, densely covered on all sides with obovate, 

 bag-like, sessile or minutely stipitate ramuli, which are nearly half an inch 

 in length, and 2-3 lines wide at the widest part. These ramuli are of a 

 firmly membranous texture, rigid and somewhat horny when dry, and when 

 young are filled with a thinly gelatinous mucus. "When old they are very 

 generally ruptured at the extremity, and are then commonly found either 

 empty or filled with sand. The cellular structure of the membrane is very 

 dense, and in a triple series of cells ; the inner lining being composed .of 

 small cells, the middle of larger, and the outer coat of minute, serrated cel- 

 lules ; all the cells are sometimes coloured, and sometimes the medial cells 

 are colourless. The conceptacles are borne on the ramuli, several often 

 occurring together ; they are hemispherical, thick-walled, with a large ca- 

 vity, through which a cobwebby network of filaments extends ; and they 

 contain a central nucleus, consisting of minute oval spores. The nucleus 

 appears divided into spaces, as if it arose (as it probably does) from the 

 confluence of several primary or mother cells. The substance of the frond 

 is rigid, and it does not adhere to paper in drying. The colour, when quite 

 fresh, is a dark brownish-red, inclining to purple, but much more commonly 

 the plant is found faded to a pale red, yellowish, or greenish, and is often 

 bleached white on the strand. 



This plant is common on several parts of the Australian coast, 

 but is rarely found in fruit. When cast ashore, and bleached 

 to a yellowish or greenish white, it strongly resembles the egg- 

 clusters of some of the Gasteropodous Mollusca, the substance 

 being horny-membranous, and most or all of the ramuli being 

 ruptured at the extremity. When young, the colour is purple, 

 and the ramuli are filled with mucus. 



It bears a very strong resemblance to Ch. uvaria, a species 

 found in the Mediterranean, the Gulf of Mexico, and on the 

 shores of tropical India, and a few fragments of which I dredged 

 in Port Jackson. Our present plant differs from Ch. uvaria in 

 colour, in more rigid substance, and in more obovate ramuli, 

 and somewhat in its cellular structure, if not also in the com- 

 pound nucleus. Still, I am very unwilling to separate it gene- 

 rically, as has been done by J. Agardh, who refers it to llhab- 

 donia ; for what reason I know not. It differs much more from 

 Bhabdonia (in my opinion, at least) than from Ch. uvaria. 



Fig. 1. Ghrysymenia obovata, — the natural size. 2. One of the ramuli, 

 bearing conceptacles. 3. Section of a conceptacle, with part of the peri- 

 phery of the ramulus. 4. Spores : — the latter figures more or less magnified. 



