do they agree in habit, that plants regarded by the elder Agardh as varieties of PL coccineum (/3 and y) are considered by his son as distinct species of Tkamnophora[1].
1. Plocamium coccineum, Lyrigb. ; Hyd/r. Ban. p. 39. t. 9. Grev. Alg. Brit. p. 12. t. 98. Hook. Brit. Fl. vol. ii. p. 293. P. vulgare, Bamottr. PI. coccineum, fenestratum, Lyugbyanum, et Binderianum, Kiitz. Phyc. Gen. p. 449 and 450.
Hab. Lord Auckland's group and Campbell's Island ; abundant.
This is the only species of the genus found in the northern hemisphere and is apparently common, especially in all temperate regions of the globe.
20. BHODOMENIA, Grev.
1. Bhodomexia Hombroniana, Mont.; "fronde cartilagineo-inembranacea plana e basi substipitata dichotoma pinnatifissa, pinnis ob axiUas obtusas patenti-erectis obtusis, margine fimbriate seu ramenta den- tata conceptaeulifera etnittente, conceptaculis bemisphericis papillula instructis." Mont. Prodr. Phyc. Antarct. p. 1. Toy. au Pole Sud, Bot. Crypt, p.157 . t. 1. f. 2. (Tab. LXXII. Fig. II.)
Hab. Lord Auckland's group ; on the stems of large Alga.
Our specimens of this plant are young, and as they differ from the more advanced state in form and in colour, we have added a figure; the colour in this state is of a beautiful red purple, sometimes inclining to violet. When fully developed, the species assumes the appearance represented by Dr. Montague in the plate quoted above. We are indebted for magnificent specimens, collected at Akaroa, to M. Kaoul.
Plate LXXII. Fig. LT. — 1. a young specimen, of the natural size; 2, 3 and 4, marginal leaflets bearing the fructification ; 5, section of the same : — magnified.
2. Khodomenia ornata, Mont.; "fronde carnoso-membranacea oblongo-lanceolata latissima plana vivide purpurea utrincjue margine prolifera, foliis s. pinnulis obovatis substipitatis tandem cuneatis maximis palmatifissis, conceptaculis per totam frondem sparsis." Mont. Prodr. Phye. Antarct. p. 1. Toy. cm Pole Sud, Bot. Crypt, p. 160. t. 11.
Hab. Lord Auckland's group. (Admiral B'Urville.)
The plant, from which the magnificent plate given by Montagne was executed, is marked by the lamented D'Urville as a native of Lord Auckland's Island, where, we regret to say, it was not collected by the Antarctic Expedition.
3. Bhodomexia dic/iotoma, Hook. fil. et Harv.; fronde membranacea rosea basi cuneata latissima dichotoma, axillis rotundatis, laciniis patentibus linearibus v. cuneatis obtusis demum emarginatis et bifidis. (Tab. LXXII. Fig. I.
Hab. Campbell's Island ; on rocks in the sea.
- ↑ I had long supposed that the sphaerospores of these genera were different ; but after a complete examination of the fruit of T. corallorhiza, costata, angusta, Mertensii, procera, CunningJiamii, Telfairia and cornnta, and comparison with that of PL coccineum, I have been obliged to abandon this idea. In all, the spharospores are cylindrical, divided into four by three transverse striae. Kiitzing separates PL cornutum under the generic name of Thamnocarpus, but I am at a loss to conceive upon what grounds. — W. H. H.
