SPIROSTOMUM. 



[ 599 ] 



SPIRULINA. 



10. S. bellis. Filaments 1-480" in diam.; 

 joints equal or twice as long ; spiral bands 

 two or three, lax; spores somewhat glo- 

 bose; var. /3, spirals condensed (Hass. 

 pi. 24). 



11. 5. pelliickla. Filaments 1-840" in 

 diam.; joints four or six times as long; spi- 

 ral baud lax and slender; fertile cells ven- 

 tricose; spore globose (Hass. pi. 25). 



12. S. rivularis. Filaments 1-2040" in 

 diam. ; joints three or four times as long ; 

 spiral bands four, broad, dense (Hass. pi. 



13. S. curvata (Sirogonium sticticum and 

 breviarticulatum, Kiitz.). Filaments 1-720" 

 in diameter, joints four or five times as 

 long ; spiral bands three or fom-, slender ; 

 conjugation dnect, without a cross branch, 

 approaching Mougeotia (Hassall, pi. 26. 

 figs. 1,2). 



BiBL. Hassall, Brit. FresTiw. Alg. p. 135; 

 Kutzing, Sj). Alg. p. 437, Tab. Phyc. v. ; 

 Pringsheim, Flora, xxxv. p. 465. 1852 (Ann. 

 Nat. Hist, ser. 2. xi. p. 210); Al. Braun, 

 Verjungung {Ray Soc. Vol. IS53, passim); 

 Meyen, Pflanzenphysiologie, iii. p. 422 ; 

 Vaucher, Conferves, p. 37; Agardh, Ann. des 

 Sc. nat. 2 ser. vi. p. 197. 



SPIROSTOMUM, Ehr.— A genus of In- 

 fusoria, of the family Trachelina. 



Char. Bod}^ cihated all over, oblong or 

 cylindrical and elongated, without a neck ; 

 mouth spiral, with neither teeth nor a tre- 

 mulous lamina. 



S. ambiguum (PI, 24. figs. 77, 78). Body 

 cylindrical and elongated, colourless, obtuse 

 in front, truncate behind, prolonged ante- 

 riorly beyond and above the mouth. Aqua- 

 tic; length 1-12". 



S. virens. Body oblong, green. Aquatic ; 

 length 1-120". 



Dujardin gives the characters : — Body cy- 

 lindrical, greatly elongated, and very flexible, 

 often twisted, covered with cilia arranged 

 upon the oblique or helical striae of the sur- 

 face; mouth situated laterally beyond the 

 middle, at the end of a row of larger cilia. 

 The genus consisting of S. ambiguum, E. 

 and /S. ( Uroleptus, 'E.)Jilum ; «S. virens being 

 placed as Bursaria spirigera. 



BiBL. Ehrenberg, Jm/m5. p. 332; Dujardin, 

 Infus. p. 514. 



SPIROT.ENIA, Breb.— A genus of Des- 

 midiaceae. 



Char. Cells single, elongated, cylindrical 

 or fusiform, straight, entne, not constricted, 

 ends rounded ; endochrome spiral. 



Division oblique. In one species the 



endochrome is spiral at first, subsequently 

 becoming uniform. 



S. condensata (PI. 10. fig. 59). Endochrome 

 forming a single broad band. Length 1-208". 

 Common. 



S. obscura. Endochrome at first forming 

 several spiral threads, afterwards uniform. 

 Length 1-240". 



BiBL. Ralfs, Brit. Desmid. 178. 



SPIRULINA, Link.— A genus of Oscilla- 

 toriaceae (Confervoid Algae), consisting of 

 minute spirally coiled filaments immersed in 

 a gelatinous matrix, having an oscillating 

 motion; forming extensive strata in lakes, 

 brackish water, &c. The intimate structure 

 and development of these curious organisms 

 are not yet well understood ; they are sup- 

 posed to increase by the filaments breaking 

 across ; in some the filament appears conti- 

 nuous ; in others it has striae, like the Oscilla- 

 torieae (appearing beadedwhen badly defined). 

 It does not appear that Ehrenberg's and 

 Dujardin's genus Spirillum consists of 

 species referable to this genus. Several 

 British species are described. 



1. S. Jenneri (PL 3. fig. 16). Filaments 

 with striae, 1-6000" in diameter, usually of 

 eight or ten coils, forming a thin aeruginous 

 stratum. 



2. )§. (?) Thompsoni. Filaments striated, 

 of rarely more than four coils, then about 

 1-50" in length (from the figure, the diame- 

 ter would appear to equal 1-2000" at least), 

 forming a greenish, then pale blue, finally 

 ferruginous stratum. Anabaina spiralis, 

 Thompson, Ann. Nat. Hist. v. p. 84. 



3. S. temiissima. Filaments not striated, 

 with close coils; coils 1-9500" in diam., 

 pale aeruginous, forming a pellicle of a rich 

 green colour, ultimately ferruginous (Ralfs, 

 Ann. Nat. Hist. xvi. pi. 10. fig. 1 ; Harvey, 

 Brit. Mar. Alg. pi. 27 C). In brackish 

 pools. 



4. S. HutchinsicB. Filaments not striated, 

 with close coils ; coils from 1-9600 to 1-1080" 

 in diam. ; forming an aeruginous stratum in 

 the sea (Kiitzing, Tab. Phyc. i. pi. 37. fig. 2). 



5. S. oscillarioides (PI. 3. fig. 15). Fila- 

 ments not striated; coils 1-7200" in diam.; 

 lax. Among Oscillatoriae in stagnant pools. 



Spirillum minutissimum and rupestre, 

 Hassall, probably belong here; but the former 

 may be Spirillum volutans of Ehrenberg. 

 These organisms require further investiga- 

 tion. 



BiBL. Kiitzing, Sp. Alg. p. 236, Tab. 

 Phyc. i. pi. 37 ; Hassall, Brit. Fr. Alg. p. 

 277. pi. 75 ; Harvey, Brit. Mar. Alg. p. 229. 



