notes on the distribution of algie. 71
Cryptonemiace^. Gigarthm mamillosa, J. Ag. | Irldcea eduUs, Bory.
Qriffithsia setacea, Ag.
��Ptilota sericea, Ktz. Cerardium ruhriim, Ag. C. acanthonotnni, Cann.
��CaUithamnion Arbuscida, Lyngb,
Bryopsis plumosa, Ag.
Cladopliora arcta, Ktz.
B. ciliaris, Carin. Growing upon Ectocarpus splicer ophor us.
��Enteromorpha compressa, Grev. Borpliyra laciuiata, Ag. Buncjia fasco -purpurea, Lyngb.
Calothrix scopulorum, Ag.
Synedra fulgens, Sm. | Isthnia nervosa, Kistz.
This list is very meagre compared with the species found on the nearest coast, where the prevailing rock is hard chalk ; the following are among the more remarkable of these, — most of them are not merely plentiful, but notable for their size :* — Laminaria jiJiylUtis, L. Fascia, Didyota dicho- toma, Stilophora rhlzodes, Punctaria latifolia, Asperococcus Turneri, Meso- gloia vermicular is, PolysipJionia formosa, P. violacea, P.elongellu, P.atro- purpurea, P. affinis, P. parasitica, Chylocladia ovalis, C. kaliformis, De- lesseria Hypoglossiim, Nitopltyllam punctatum, N. Bonnemaisoni, N. Gme- lini, Rhodymeuia ciliata, Sphcerococcus coronopifolius, Cliondrus Norvegi- cus, Ilalymenia Ugulata, Scinaia furcellata, Kallymenia reniformis, K. Duhyi, GloiosipJionia capilla?'is, CalHthamnioii Plumula, C.fioridulum, G. cruciatum, etc. etc.
The species already mentioned as found on the " Maidens" are gene- rally very dwarf; they also grow on the nearest coast, where they attain much greater size. Hard chalk being the prevalent rock in the one case, and rugged basalt the habitat in the other, the contrast as to size, as well as number, might be attributed to difference in chemical composition ; the small e,\.tent of surface at the " Maiden Rocks," freely exposed to all the storms of the Channel, and therefore unfavourable to the growth of many species, is the most probal)le cause ; on the Antrim coast sheltered pools and crevices abound, and tlicse day after day in summer, during ebb,
Candolle in 1824, S. O. Gray, in a popular account of British Algse, has given tlie name Maugeria, in honour of a lady collector ; I follow Le Jolis's ' Alga) of Cher- bourg,' in adopting Stackhouse's name, Tentamen, etc., 1809.
- See Memoir of late Professor Harvey, p. 220, in a letter he alludes to the size
of Rhodgmenia laciniata, Grrev. ; a specimen from coast of Antrim large enough to cover an ordinary round drawing-room table.