106 OSCILLATORIACEtE. 



3. Calothrix vivipara, Harv. ; spreading in continuous, velvetty strata ; filaments 

 thick-walled, fasciculate at base, straight or somewhat curved, viviparous above, and 

 pseudo-branched ; endochrome strongly annulated. 



Hab. Seaconnot Point, Professor Bailey (v. s. in Herb. T.C.D.) 



This appears to form a continuous stratum on rocks, like that of C scopulorum, but 

 the filaments of which it is composed are longer, 2-3 tenths of an inch long and straighter ; 

 more united at the base into fascicles, and furnished above with appositional branches 

 which evidently rise from viviparous separations from the endochrome. Sometimes the 

 endochrome seems to split or divide longitudinally ; at other times it separates trans- 

 versely, the portions growing at each end and cohering laterally. The cell-wall is wider 

 than in C. scopulorum. 



Certainly closely allied to C. scopulorum and also to C. hypnoides, and perhaps 

 intermediate between them, connecting the extreme forms of each. It was sent to me 

 bv Professor Bailey as probably C. fasciculata, but it does not agree with the British 

 plant so called ; and not knowing what else to do with it, being unwilling to pass it by 

 altogether, I have given it a provisional locus in the genus, assigning to it the trivial 

 name vivipara. It may possibly be merely a viviparous state of C. scopulorum. 



4. Calothrix pilosa, Harv. ; strata of indefinite extent, blackish or dark brown, 

 pilose ; filaments densely interwoven at the base, then free, elongate, rigid, cylindrical, 

 very obtuse, very flexuous, simple or slightly pseudo-branched ; cell-wall very thick, 

 fulvous or subopaque ; endochrome narrow, dark green. (Tab. XLVIII. C.) 



Hab. On rocks between tide marks, Key West, W.H.H. (v. v.) 



This forms strata of indefinite extent, covering rocks in patches of a very dark 

 blackish or brown colour, not in the least lubricous, and more pilose than velvetty. The 

 stratum is about quarter of an inch thick ; its matrix composed of the densely inter- 

 woven decumbent bases of the filaments which constitute it. These are afterwards 

 erect, unconnected together, standing separately like the hairs on a fleece, very much 

 curved or twisted, nearly half an inch long, rigid and not at all slimy. They are about 

 the same diameter as L%jnghya majuscula ; and are scarcely attenuated at the blunt 

 apex. The cell-wall or tube is remarkably thick and opaque, evidently formed of 

 successive deposits, indicated by faint longitudinal stria3 ; and is fulvous or ochraceous 

 in colour. The endochrome seldom constitutes more than a third of the diameter of 

 the filaments, and is of a dull dark-green, more or less annulated. When dry the whole 

 plant is rigid and harsh, and does not adhere to paper. 



This seems to be a well characterised species, difierent at least from any with which 

 I am acquainted, and to be recognised by its shaggy, rigid pile of hair-like filaments, 

 and their dark colour. Its microscopic characters are quite different from those of 

 C. scopulorum. It abounds at Key West on littoral rocks. 



