DELESSERIA. 115 



ils surface marked, in luxuriant specimens, with evident transverse striae. 

 Colour a deep red. Tubercles splierical, attached to the midrib, generally 

 near the ends of the branches ; tetraspores imbedded in little leafy processes 

 of the midrib, generally at or near the tips ; sometimes in the tips them- 

 selves. 



4. D. angustissima, Griff. ; frond membranaceo-cavtilagi- 

 nous, compressed, very narrow, two-edged, much branched ; 

 branches alternate, distichous, of unequal length, much di- 

 vided above, and furnished with numerous forked ramuli ; 

 tubercles imbedded either in the tips of the frond, or in small, 

 axillary ramuli ; tetraspores forming sori either in the inflated 

 apices, or in axillary, lanceolate ramuli. Harv. Phyc. Brit, 

 t. Ixxxiii. Del. alata, y. angustissima, Grev. Alg. Brit. p. 

 74. Gelidium ? rostratum, Griff, in Harv. Man. ist ed. 

 2J. 82. 



On the stems of Laminaria digitata. Perennial. Winter and Spring. 

 North of Scotland and east coast of England. — Fronds 4 — 8 inches long, 

 not half a line in diameter, nearly cylindrical below, compressed and two- 

 edged above, much branched. Branches distichous, alternate or dichoto- 

 mous, or somewhat pinnate. Colour dark red. Substaiice cartilaginous. 

 I admit this plant in deference to the opinion of Mrs. Griffiths, who con- 

 siders it permanently distinct from the preceditig, by the above characters. 

 To me it appears merely an extreme variety of a variable plant. 



5. D. Hypoglossum, Woodw. ; frond much branched in a 

 proliferous manner, composed of linear-lanceolate, midribbed 

 leaves, tapering at each end, the younger series springing 

 from the midribs of the older; tetraspores forming an oblong- 

 line at each side of the midrib, near the tips of the leaves. 

 Hook. Br. Fl. ii. p. 286 ; Wyatt, Alg. Danm. No. 63 ; Harv. 

 Phyc. Brit. t. ii.; E. Bot. t. 1396. 



On rocks and other Alga, not uncommon on the shores of England and 

 Ireland; rare in Scotland. Annual. Summer. — Fronds several from the 

 same base, at first forming a simple, linear-lanceolate leaf, furnished with 

 a distinct midrib, and faintly marked by pellucid transverse veins; after- 

 wards excessively branched, and forming globose tufts 4 — 6 inches in 

 diameter; the branches or leaves springing from the midrib of those first 

 formed, resembling them in outline, and bearing from their midribs a se- 

 cond and third series. Colour a fine pinky-red, soon given out to fresh 

 water. Tubercles ^\ohos,G, seated on the midrib about the centre of the 

 leaflet ; tetraspores disposed in linear longitudinal lines or sori, at each side 

 of the midrib, often near its end. Some of Miss Hutchins's specimens, 

 gathered at Bantry Bay, are of very large size, the primary leaf being 

 t) — ^8 inches long, and half an inch wide. In the common varieties the 

 leaves are seldom more than two lines, but frequently only a line in 

 breadth. 



6. D. ruscifolia, Tin-n. ; frond branched in a proliferous 



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