KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 63. NO 8. 9 



ad 2 cm longis et latis, aliis minoribus, basi cordata, in stipitem cuneatum subiter an- 

 gustata. Structura anatomica sat typica (vide inf ra). Spermatangia ignota. Cysto- 

 carpia immersa, 90 — 135 \l diam., carposporis 8 — 10 [j.. Tetrasporangia nt in sect. Rho- 

 doglossum, late ovoidea-ellipsoidea-cylindrica, matura 25 — 70 jx longa et 20 — 35 [x lata. 

 Crassitudo laminae c. 400 \>.. Golor obscure ruber. 



South Georgia: Cumberland Bay, Moraine Fiord, drifted (18.4.09, ©); 

 »Pinguin Bay, nördl. Strand der Landzunge», 3. 7. 1883 ($, Dr. Will. ). 



I possess three specimens, only one being complete: 



L a m i n a Length of Size of larger 



Length Width stipe lobes 



1 11,5 cm 11 cm 4X5 mm 



2 — 5 cm 9 mm 3 — 4X3 — 5 mm 



3 11 cm 11,5 cm 8 mm 10 — 20 mm 



No. 3 is figured. 



The most obvious feature in the external appearance of this species are the trian- 

 gulär lobes. The small sori are scattered över the entire frond. They are not so deeply 

 immersed as in other species: they arise from subcortical, regular cell-chains and present 

 a more regular appearance than in /. cordata or allied forms, while the same arrangement 

 is found in Rhodoglossum (comp. J. Agardh, Florid. Morphol. t. 11, fig. 2), but the habit 

 of other Rhodoglossa is different. In Will's collection (Herb. Hamburg) I found one 

 cystocarpic frond, irregularly lobed and without stipe; the largest diameter is 17 cm 

 (dry). There is, as far as I can see, nothing in Reinsch's paper that corresponds to 

 this Iridaea. 



The anatomical structure does not offer anything very peculiar, but differs some- 

 what from other species examined by the writer. There is, in /. macrodonta, a central 

 medullary lamella of longitudinal cell-rows, and the radial cortex filaments contrast 

 sharply with the medulla, while in /. cordata etc. we find a broad transition zone of 

 reticulate hyphae connecting cortex and medulla, wiiich is much less distinct. The 

 sterile cortex of /. macrodonta is very like the figure of /. latissima in Grunow, Alg. 

 No vara t. 9. 



Distribution: S. Georgia. 



Gigartina Stackh. 



(i. radula (Esp.) J. Ag. — Kylin & Skottsb. p. 8. 



Sublitoral, only found in beach drift. F u e g i a : Slogget Bay (St. 47 b, 16. 3. 

 09, ©); Tekeenika, Allén Gardiner Bay, enormous f ronds, that bear root-like hapteres 

 on one surface (11. 3. 09,® ). Falkland Islands: Port Philomel, Halfway Co ve 

 (21. 11.07, $). 



Distribution: Calif., Fuegia, Fal kl., the Cape, Kerg., New Zeal. and subant. islands, 

 Graham Land. 



G. Chamissoi (Mert. ined., Ag.) J. Ag. Alg. Medit. et Adriat. (1842) p. 104. 



K. Sv. Vet. Akad. Handl. Band 63. N:o 8. 2 



