176 FLORA ANTARCTICA. [Auckland and 



lately been erected into a distinct genus, by Kiitzing, under the name of Plerocaulon, and on grounds equally valid 

 with those which separate some of the above groups. Seirococcus was distinguished from Scytothalia by Dr. 

 Greville, by having moniliform instead of oblong or lanceolate receptacles ; but the genera have been reunited by 

 Montague, who has added a new species (Scyt. Jacquinotii) , and this last approximates so closely to Marginaria, 

 as to reduce the clearly appreciable differences between Scytothalia, Mont., and Marginaria, to the former having 

 entire and the latter spinuloso-dentate margins, — a circumstance of very minor importance, and perhaps of specific 

 value only. Carpopliyllum, may be distinguished by the position of its vesicles and the clustering of its receptacles 

 from Fucus ; on the other hand it approaches Sargamim through S. Boryi, Ag. Marginaria contains but two 

 species, of which Kiitzing in his late work constitutes as many genera. A. Richard, on the contrary, struck with 

 the slight characters on which he had established Marginaria, afterwards combined it with Sargassum. 



The paraphyses, so carefully described by Montagne in the generic character as occuring mixed with the spores, 

 answer well to the antheridia observed lately by MM. Decaisne and Thuret in Fucus, whence this species would be 

 regarded by these authors as hermaphrodite. 



1. Mahginapia Urvilleana, A. Rich.; Montagne Prodr. P/tycear. in itin. ad Polum Antarct. p. 10. 

 Voy. an Pole Sud, Pot. Crypt, p. 60. t. 3. f. 1. A. Rich. Fl. Nov. Zel. p. 10. t. 3. Sargassum Urvilleanum, 

 A. Rich. Serf. Astrolab. p. 138. A. Cunn. in Hook. Comp. to Pot. Mag. vol. ii. p. 327. 



Hab. Lord Auckland's group ; very abundant in shallow water. 



Pinna 12-18 unc. longee, £-1 unc. lata?, coriaceo-membranacese, nigro-fusca3j plana?, laeves, enerves, argute 

 serratae, obtusae, basi sensim attenuates, subpetiolatas, irregulariter dichotome fissae, ramis superioribus plerumque 

 simplicibus, inferioribus divisis, sinubus angustis rotundatis, laciniis erecto-patentibus. Vesicula sphaericae, 4-8 lin. 

 latae, muticse, petiolo inconspicuo piano 1 lin. longo suffultae, margine pinnulamm superiori affixae. Receptacula 

 breviter peduncidata, 2-3 lin. longa, ad basin frondis secus marginem superiorem in serie elongata inserta, divaricata, 

 lanceolata, obtusa, compressa, torulosa. Conceptacula globosa, receptaculis immersa, demum plus minusve convexa, 

 poro pertusa. Spora exemplaribus nostris immaturaa. 



Dr. Montagne enumerates Blossevillea retorta, Mont., and B. retrofiexa, Kiitz., as natives of Lord Auckland's 

 sjroup, and also the Carpopliyllum macrophyllum, Mont. 



2. D'URYLLLEA, Pory. 



1. D'Urvillea utilis, Bory in Duperrey Voy. Pot. Crypt, p. 65. 1. 1 and 2. f. 2. If Urville, Fl. Ins. Mai. 

 in Mem. Soc. Linn. Paris, vol. iv. p. 594. Montagne, Crypt. Poliv. et in Voy. au Pole Sud, Pot. Crypt. 

 p. 23. Decaisne in Arcldv. 3Ius. vol. iv. p. 153. t. 5. f. 1-6. Postels et Rnppr., Illust. Alg. t. 1. Fucus 

 antarcticus, Ckamisso in Choris, Toy. Pittor. t. 7. 



Hab. Lord Auckland's group and Campbell's Island, and in the open sea for ten degrees southward 

 of these groups. 



The distribution of this species will be considered with that of the genus Macrocystis in the second portion of 

 the Flora Antarctica. 



3. XIPHOPHORA, Mont. 



Frons olivacea, linearis, compresso-plana, coriacea, dichotome ramosa. Vesicida nullae. Conceptacula per totam 

 frondem sparsa, ramis immersa, tuberculiformia, poro pertusa, intus naturae diversae ; altera sporas obovatas, nigro- 

 fuscas, demum quadripartitas, limbo hyalino cinctas, parietibus affixas, sessiles ; altera fasciculos filorum ramosorum, 

 articulatorum, apicibus turgidis et demum in corpuscula granulis repleta (antheridia vel gemmas) mutatos foventia. 



We fullv agree with our excellent friend Montagne in the propriety of establishing the present genus, and 



