Lyngbya.) ALOfi CONFERVOiDE^. 369 



apices cohering in rigid erect tooth-like fascicles. — Scytonema 

 hydnoides, Carm. MSS. cum icon. 



On the clayey sea-shore, at the flood-level. Appin, Captain Carrnichael. 

 — " This species occurs in thin dark olive-coloured (black-green under 

 the microscope) patches, from half an inch to 2 — 3 inches in diameter. 

 Filaments much branched, the lower part interwoven into a thin stratum 

 mixed with the clay over which they creep ; while theterminal branches 

 stand erect in close conical tufts, resembling the teeth of a Hydnum." 

 Carm. MSS.— \ have ventured to remove this plant from the genus 

 Scytonema, in which it was placed by its acute discoverer, because the 

 branches are oppositional, and the microscopic colour of the filaments is 

 of that peculiar shade of green so prevalent in the Genera Calothrix and 

 Oscillatoria, and which does not occur in any acknowledged Scyto- 

 nema. 



11. C. distorta, Ag. {large verdigris Calothrix'); filaments 

 elongated bluish-green forming large tufts mucous somewhat 

 rigid branched, branches erect flexuose. Ag. Syst. Alg.p. ~'2. — 

 Conferva distorta, Lillw. Conf. t. 22, and Suppl. t. A. — E. Bot. 

 t. 2577. 



" In fresh-water, on stems, &c, rather rare. — Filaments half to one inch 

 high, forming continuous tufts about the stalks on which they grow, 

 of a dark-green hue (when dry of an intensely verdigris or blue-green 

 colour), slender, bundled, curved and tortuous, more or less branched 

 by apposition, the branches suhsimple, elongated. Stria: more or less evi- 

 dent, in some specimens inconspicuous. 



12. C. mirdbilis, Ag. (.small verdigris Calothrix); filaments 

 abort dark bluish-green curvato-flexvoae and geniculate vari- 

 ously united, forming lax globular tufts. — Ag. Syst. Alg. />. 72. 

 — Conferva mirahilis, DUlw. Conf t. 96. (not of E. Bot. i. 2219.) 



On mosses, &c, in small streams; rare? — Filaments forming minute 

 tufts, half an inch in diameter, of a dark bluish-green colour, 

 irregularly contorted, forming geniculations with very obtuse angles, 

 here and there appositions! iy united into a vague net-like ramification, 

 apices obtuse. I am but little acquainted with this species, bating de- 

 scribed it from a specimen marked by Dillwyn, whose figure U very 

 characteristic 



13. ('. caspitula, Uarv. (globvictr-tuJUd Calotkria >.• filaments 

 forming close convex tufts blackish-green flexuose Aaooid <d>- 

 tuae here and there spuriously branched. 



Marine rocks, below high-water mark. Miltowu Malbay, rare, Jr. //. 

 Harvey*— Tufta wery cohma, J— I } inch in diameter, deep blackish- 

 green, flaccid, growing on the naked rock or attached to coralline-. &c 

 Filaments denselj packed together, often twisted round each other in 

 small bundles, either simple or paeudorbranched, obtuse, cylindrical, 

 branches erect Striae very strongly marked and closeh set Not un- 

 like Rivularia atra in it ^ habit, at a short distance, but ita softness and 

 flaccidit) will at once distinguish it to the touch. 



71. L\ \..i,-, \. . iff, L] ngb\.i. 



I '/ In mi R/!r destitute of a mucous layer, inr, flexible, elongated, 

 continuous, decumbent. Endochronu (green or purple) deni 



2 D 



