NEW OR CRITICAL BRITISH MARINE ALGH 8 
swollen, and deeply coloured, whilst the basal cells are very slender 
and colourless. Again, in M. Grifithsiana the spores are only about 
one- third the height of the cortical filaments, in M. neglecta a 
are very nearly as high as the surrounding filaments. A good i 
of the diltstuness between the two oni can be got by an 7% 
amination of figures 7 and 8 of the plate 
8. Droryora sprratis Mont. Alger, p. 29. Plate 475, figs. 1 
and 2. In August, 1901, at Sidmouth, and again at Torquay in 
August, 1902, I found a Dictyota which in most : respects resembled 
D. dichotoma, but differed from it in ne all the edges of the 
fronds thickly covered with a dense coating of hairs. My <htere 
agree so well with the description of D. sivas that I have n 
— in rehabitng them to that Don or vari 
. AcrocHztium Atarim (= Chantransia late Tons. Marine 
hige of Iceland Cictaniak Tidsskrift, cy, 132)). This species has 
been recorded from Ireland in a recent number of this Journal 
J. Adams, Journ. Bot. 1904, 851). But it has not, I think, been 
noticed that Harvey found at Miltown Malbay, some time before 
1838, what he calls (Hooker, 2 aed a p. 349) Callithamnion 
secundatum on Alaria esculenta. o doubt that the plant 
referred to by caged was really 4. Alaria, although no proof of the 
fact can now be obtained. I found the plant covering large surfaces 
of 8 or of ‘Alia at Berwick-on-Tweed in August, 1904. 
spec 8 grew in company with Ectocarpus confervoides Le Jol. var. 
Sse : Kjeltin,, and an equally stunted form of Ectocarpus Hincksia. 
10. Raopocnorton pENICcILLIFoRME (Kjellm.) Roseny, Algues 
. Mar. du Greenl. P. 66 (Ann. Sci. Nat. % 8, t. 19). Amongst some 
specimens of marine alge sent to me from St. Mary’s, Scilly, in 
September, 1899, re the late Mr. E. George, are some beautiful 
specimens of the above species growing on a Sertularia. I have 
11, Ruopopermis ELEGANs Crouan var. Zostericota Batt. in 
herb. At Weymouth in ree gust, 1900, and again at Torquay in 
— I found on (sks fronds of. Zi cateett marina, & variety of R. elegans, 
h differs from typical specimens in forming only a very narrow 
ae along the edges of the fronds of the host-plant, never 
spreading out into wide expansions. 
: }. EXPLANATION OF zone 475. 
Fie. 1 st ah yee Scale pain 
- - Ap of the edge of a frond of trie & 
100. 
ao A 30 snore be ell of ae tomentosum with Diplocoton Codii, x 150. 
Fias. 4,5. Portions of a frond of —— Codii more y magnified. 
Fie. 6. Portion of the same show 
» 7% A-small portion of a transverse s section through the frond of Mesogloia 
neglecta, showing cortical filaments and spores, x 
8. oo of a similar section though the e frond of Mesogloia Grigith- 
; , for comparison. with fig. 7. 
B2 
