midribbed, strap-shaped frond, which is either once or twice forked, or else 

 simple, and is throughout its length laxly set with distichous branches. 

 These branches are flattened and midribbed like the stem, and are either 

 entire at the edge or subdenticulate ; they are 6-12-18 inches long, irre- 

 gularly pinnated with alternate or scattered secondary branches ; and the 

 latter bear a third or fourth series of similar but smaller ramifications. 

 All the lesser branches are much constricted at base, linear-strapshaped, and 

 obtuse or subacute ; the ultimate ramuli are scarcely an inch long, linear- 

 oblong or somewhat lanceolate. The substance is firmly coriaceo-cartilagi- 

 nous, pliant and tough when recent, horny when dry. The conceptacles are 

 imbedded in the ultimate ramuli, three or four or more in each ramulus ; a 

 slight wartlike swelling, pierced with a pore, indicating the place of each. 

 The sporular mass is suspended among the interwoven threads of the me- 

 dullary stratum, and surrounded by a plexus of filaments ; outside which, in 

 some specimens (as in the one figured) there occurs a stratum of pseudo- 

 tetraspores (?), or quadripartite, coloured cellules, which would pass for 

 tetraspores if found on separate plants. The sporular nucleus is formed 

 of radiating strings of spores, issuing from a central, cellular placenta. 

 Colour, when growing, a clear, deep red, which becomes darker in drying, 

 and fades, through orange and yellow, to creamy-white, after long exposure. 

 The frond does not adhere to paper. 



This handsome plant forms the type of a genus which I dedi- 

 cated, in the herbarium, many years ago, to my friend Profes- 

 sor Areschoug of Upsal, but only published a character of it in 

 1855. Very recently, my friend Dr. Sonder, of Hamburg, has 

 informed me that my "Areschougia conferta, Alg. Austr. n. 385" 

 is identical with his "Nizymenia australis, Linn. v. 26, p. 521," 

 a name published in 1853, and which had not reached me when 

 my genus was established. But here a difficulty arises ; for I 

 find that I have distributed two plants under the MSS. name 

 "A. conferta /' and had already discovered, and, as I supposed, 

 corrected, the error in the (still unpublished) letterpress of the 

 ' Flora of Tasmania,' by retaining some specimens to A. conferta, 

 and naming the others "Prionitis ? rubra? It is possible that 

 this latter may be the type of Sonder's Nizymenia. If so, the 

 name Areschougia will stand at least for the present plant and 

 for A. Laurencia. The genus appears to me to be nearly allied 

 to Bhabdonia, from which it is readily known by the articulated 

 monosiphonous axis. The structure of the frond is similar to 

 that of Phacelocarpus, but the fructification very different. 



Fig. 1. Areschougia australis, — portion of a frond, of the natural size. 

 2. Cross section through an old stem. 3. Longitudinal section of the 

 same. 4. Cross section of a fertile ramulus, through one of its concep- 

 tacles, which is surrounded by a band of pseudo-tetraspores. 5. Strings of 

 spores, from the nucleus. 6. Pseudo-tetraspores : — the latter figures va- 

 riously magnified. 



