247 



Oscillaiia tenexxima. Kutz. Tab. Phyc. i., t. 38, f. 8. 



Solitary and scattered, or associated in fascicles. Trichomes 

 straight, indistinctly articulate, joints equal in length to their 

 diameter, or a little longer or shorter, ends somewhat acute, 

 slightly inclined ; cell-contents pale blue green, or olive, homo- 

 genous or very finely granular. 



SIZE. Threads -0018--0025 mm. diam. 



Rabh. Alg. Eur. ii., 96. 



In ditches, amongst decaying vegetable matter. 

 Plate XCVI. fig. 4. Trichomes X 400. 



Oscillaxia leptotxicha. Kiitz. Tab. Plujc. i., t. 38, /. 9. 



Solitary, scattered, or collected in a very thin bine green 

 stratum, trichomes very slender, slightly curved, indistinctly 

 articulate, joints twice as long as broad, or after division equal, 

 very minutely punctate at the periphery, attenuated at the ends, 

 which are straight, curved, or deflexed, cell-contents pale blue, 

 green, homogenous or finely granular. 



SIZE. Threads -003 mm. diam. 



Rabh. Alg. Eur. ii., 97. 



In fresh or brackish ditches. 

 Plate XCVI. fig. 5. Trichomes X 400. 



var. splendida. ("Grev. Fl. Edin. 304. J 



SIZE. Trichomes not exceeding -002 mm. diam. 

 Oscillatoria splendida, Eng. Fl. v., 375. Harv. Man. 164. 

 Hass. Alg. 251, t. 72, f. 8. 



In tubs of water in a stove. Edinburgh Botanic Gardens. 

 Plate XCVI. jig. 6. Trichomes X 400. 



Oscillaxia spixalis. Carm. Harv. Phyc. JBritt. t. 105s. 



Effused in a firm coriaceous glossy black stratum. Trichomes 

 radiating, slender, long, flexuous, regularly twisted in spirals. 

 SIZE. Threads -0035--004 mm. diam. 

 Spirillum rupestre, Hass. Alg. 277, t.^75, f. 6. 

 Spirulina rupestre, Rabh. Alg. Eur. ii., 93. 



On rocks by the seaside. 



" It spreads over the dry naked earth. Stratum several feet in extent, 

 firm, coriaceous, of a glossy black colour, void of lubricity. Filaments 

 about half a line in length, twisted like a corkscrew, radiating 111 all di- 

 rections." Carmichael. 



Plate XCVIII. fg. 7. Trichomes X 400, from the original specimens. 



