Ser. RHoposPpERME2. Fam. Rhodomelee. 
Puate XXXIV. 
ODONTHALIA DENTATA, Zyngs. 
Gey. Cuar. Frond plano-convex, two-edged, vinous-red, distichous, obso- 
letely ribbed, alternately toothed at the margin, cellular; central and 
surface-cellules minute, irregular. /ructification two-fold, on distinct 
plants; 1, capsules (ceramidia) furnished with a terminal pore and 
containing a mass of pear-shaped spores ; 2, lanceolate pods (stichidia) 
containing tripartite tetraspores in a double row. ODpoNTHALIA 
(Lyngb.)—from 6dovs, a tooth, and pddos, a germ or branch. 
OponrHatta dentata; frond irregularly pinnate; branches linear-oblong, 
deeply pinnatifid; lacinie alternate, sharply toothed towards their 
truncate extremities ; capsules and pods clustered, axillary or marginal. 
OvONTHALIA dentata, Lyngb. Hyd. Dan. p. 9. t. 3. Grev. Fl. Edin. p. 296. 
Grev. Alg. Brit. p.101. t.13. Hook. Br. Fl. vol. ii. p. 293. Harv. Man. 
p- 66. Kiitz. Phye. Gen. p.448. Endl. 3rd Suppl. p. 47. 
Ruopometa dentata, 4g. Sp. Aly. vol.i. p. 370. Ag. Syst. p. 196. Spreng. 
Syst. Veg. vol. iv. p. 342. 
DE.LEssERIA dentata, Lamour. Ess. p. 36. 
Fucus dentatus, Lin. Syst. Nat. vol. ii. p. 718. Huds. Fl. Ang. p. 582. Lightf. 
Fl. Scot. vol. ii. p. 952. With. vol.iv. p.102. Linn. Trans. vol. iii. p. 158. 
Turn. Syn. vol.i. p. 149. Stack. Ner. Brit. p.95.+.15. #. Bot. t. 1241. 
Turn. Hist. t. 13. 
Fucus atomarius, Gmelin. Hist. Fuc. p. 125. t. 10. f. 1. 
Fucus pinnatifidus, FZ. Dan. t. 354 (eael. Syn. Huds.). 
Has. On rocks in the sea. Perennial. Fruiting in winter. Abundant 
on the shores of Scotland, and of the north of Ireland. Coast of 
Durham and Northumberland, rare, Wr. Winch. 
GrocrR Dist. Coast of northen Europe. Iceland. North America, Gmelin. 
Descr. Fronds rising from a hard disk, tufted, 3-12 inches long, much 
branched, furnished with an imperfect mid-rib below, which gradually be- 
comes fainter upwards, flat and membranaceous above; the main stem 
simple, or forked 2—4 lines wide, alternately toothed. Branches issuing 
from the axils of the teeth of the main stem, tapering at the base, simple 
or subdivided, deeply pinnatifid; the /acinie erecto-patent, linear, entire 
for more than half their length, alternately toothed above, the larger ones 
pinnatifid, with toothed segments; teeth very acute, erect. Fructification 
born along the margin, or confined to the axils of the teeth, on slender, pel- 
lucid stalks, which are either simple or branched, solitary or tufted.  Cap- 
sules somewhat pitcher-shaped, with very wide mouths, containing a cluster 
of dark red, pear-shaped spores; s¢ichidia lanceolate, nearly colourless, 
containing a double row of dark purple tetraspores. Substance cartilagineo- 
membranaceous subcoriaceous scarcely adhering to paper. Colour a deep 
vinous-red, becoming darker in drying. The sme// is agreeably pungent, 
but the taste is insipid. 
PIII III IPRA 
162034 
