LYNGBYA. 225 



attenuated to a long setaceous point. They are sometimes simple, but 

 more generally furnished with 26 erect, closely pressed, pseudo-branches ; 

 the striae are strongly marked and very closely set. The filaments, in my 

 specimens, are longer, straighter, more acuminated, and of a darker colour 

 than I find them in an authentic specimen from Agardh. 



6. C. pannosa, Ag. ; filaments long, rigid, very much curled 

 and twisted, obtuse, densely interwoven together into lamel- 

 lated tufts or honeycombed strata ; endochrome dark green, 

 densely annulated. Harv. Phyc. Brit. t. Ixxvi. 



Near high-water mark, growing on rocks or on Fucus canaliculatus. 

 Roundstone Bay, Mr. Mc'Calla. Filaments half an inch long, very much 

 curled, intricately woven together into laminated bundles, formed into a 

 sort of honeycombed stratum. I omit here the Sidmouth and Kilkee habi- 

 tats given in the ' Phycologia,' the specimens fro 

 a new examination, and being possibly distinct. 



7. C. hydnoides, Carm. ; filaments elongated, flexuous, 

 cylindrical, obtuse, interwoven at the base, the tips cohering 

 in rigid, erect, tooth-like fascicles. Harv. 1. c. p. 369. Scy- 

 tonema hydnoides, Carm. MS. cum icone. 



On the clayey sea-shore, at the flood level. Appin, Capt. Carmichael. 

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

 microscope) patches, from half an inch to 2 or 3 inches in diameter. Fila- 

 ments much branched, the lower part interwoven into a thin stratum mixed 

 with the clay over which they creep ; while the terminal branches stand 

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

 This plant is allied to C. scopulorum, but has a very peculiar habit. 



8. C. caspitula, Harv.; filaments forming close, convex 

 tufts, blackish-green, flexuous, flaccid, obtuse, here and there 

 spuriously branched. Harv. I. c. p. 369. 



Marine rocks near high-water mark. Miltown Malbay, rare. Tufts very 

 convex, J 1 inch in diameter, deep blackish green, flaccid, growing on 

 the naked rock, or attached to corallines, &c. Filaments densely packed 

 together, often twisted round each other in small bundles, either simple or 

 pseudo-branched, obtuse, -cylindrical ; branches erect. Strim very strongly 

 marked and closely set. 



IV. LYNGBYA. Ag. [Plate 26, E.] 



Filaments destitute of a mucous layer, free, flexible, elon- 

 gated, continuous, decumbent. Endochrome (green or purple) 

 densely aunulated, and finally separating into lenticular spo- 

 rMfea. Name, in honour of H. C. Lyngbye, author of an 

 excellent work on the Algae of Denmark. Distinguished 

 from Oscillatoria by its long, flexile filaments, and from Ca~ 

 lothrix by its stratified habit. 



Q 



