Ser. RHopOsPERMEA. Fam. Spongiocarpee. 
Prats XCV. 
POLYIDES ROTUNDUS, Grev. 
Gun. Cuar. Root an expanded disc. Frond cylindrical, dichotomous, car- 
tilaginous, solid, the axis consisting of densely packed, longitudinal, 
interlacing and anastomosing filaments; the periphery of coloured, 
horizontal, dichotomous filaments, whose lower half is composed of 
large, elliptical cells; their upper of much smaller, submoniliform 
cellules. ructification, of two kinds, on distinct individuals; 1, 
oblong, irregularly formed, external warts, composed of dichotomous 
filaments, through which are scattered elliptical faved/e, having a 
broad pellucid limbus. 2, cruciate ¢e¢raspores immersed, at intervals, 
among the filaments of the periphery. Potyrpes (4y.),—from modu, 
many, and ida, form or appearance; a name ill applied to the present 
genus. 
Potyipes rotundus. 
PotyipEs rotundus, Grev. Alg. Brit. p. 70. t.11. Hook. Brit. Fl. vol. ii. 
p- 284. Wyatt, Alg. Danm. no.161. Harv. in Mack, Fl. Hid. part 3. 
p-190. Harv. Man. p. 43. 
Poty1pEs lumbricalis, 4g. Sp. Alg. vol. ii. p. 392. dg. Syst. Alg. p. 194. 
Spreng. Syst. Veg. vol. iv. p. 344. Endl. 3rd Suppl. p. 38. 
SPoNGIOCARPUS rotundus, Grev. Fl. Edin. p. 286. 
FurRcELLARIA rotunda, Lyngb. Hyd. Dan. p. 49. 
Fource.iartia lumbricalis, Kitz. Phyc. Gen. p. 402. t. 72. 
CnorpaRtia rotunda, Hook. Fl. Scot. part 2. p. 97. 
GIGARTINA rotunda, Lamour. Ess. p. 49. 
Fucus rotundus, Gm. Hist. p. 110. t. 6. f.3. (excl. syn. Huds. and Rai.) 
Linn. Syst. Nat. Gm. p. 1383. With. vol. iv. p.110. Turn. Syn. Fuc. 
vol. ii. p. 309. Turn. Hist. t.5. EH. Bot. t. 1738. 
Fucus radiatus, Good. and Woodw. in Linn. Trans. vol. iii. p. 202. Stack. 
Ner. Brit. p. 89. t. 14. 
Fucus caprinus, Gunn. Fl. Norv. vol.i. p. 96. 
Fucus fastigiatus, Herb. Linn. (sec. Turn.) Esper, t. 16 (excl. syn.). 
Has. On rocks in pools, within the tide range. Perennial. Winter. 
Frequent on the shores of England and Ireland. Jersey, Miss White 
and Miss Turner. Rare in Scotland? Appin, Capt. Carmichael. 
Dumfries, Sir J. Richardson. Frith of Forth, Wr. Maughan, Mr. 
Stewart, Dr. Greville. Aberdeen, Dr. Dickie. Orkney, Rev. Mr. 
Clouston, Rev. Mr. Polleafen, Iieut. Thomas, Dr. Me Bain. Ardros- 
san, Major Martin, and Rev. D. Landsborough. 
Goer. Distr. Atlantic shores of Europe from Iceland to France (and Spain ?). 
Atlantic shores of North America. Boston, Mr. Emerson. New York, 
Prof. Bailey. Adriatic Sea, Wulfen (omitted by J. Agardh). 
Descr. Root a fleshy, flattened, circular disc, half an inch or more in diameter. 
IB 
