BY G. 



PLATFAIR. 



139 



cent for a short time, tlien gradually coil into non-motile spirals, 

 which finally, after some spasmodic movements, become active. 

 I have watched the whole process. 

 Lismore(3, 11, 12). 



Var. MAXIMUM n.var. (PI. vii., f.8). 



Long. s. flag. 50; diam. anfract. 14, diam. fil. H/x. Anfractibus 

 3; in extremis flagello distincto praeditum. 

 Casino (14). 



Spirillum tenue Cohn. (PI. vii., f.9). 

 Long. s. flag. 10; diam. anfr. 3, diam. fil. 1 /x. Anfract. 2. 

 Lismore(20); Coraki, river-brink, in Spimdiyia stra.t\iin (27). 



Spirillum laxissimum n.sp. (PI. vii., f 10). 



Trichomata brevissima hyalina in spiram regularem laxissimara 

 contorta; anfractibus semper singulis. 



Long. s. flag. 4-8; diam. anfr. 2-3; diam. fil. |-1 /x. 



Long. s. flag. 10-16; diam. anfr. 3-4; diam. fil. IJ/x. 



Lismore(16), both forms together in quantity. 



I have always taken this to be Spirillum undula Cohn, and 

 indeed that name would describe the plant very well. However, 

 reference to Q. Journ. Micr. Sci., n.s., Yol. xiii., PI. v., shows 

 that Sp. undula {i. '20) cannot be distinguished from Sp. tenne 

 Ehr. (f.l9;, and must be considered, therefore, as a synonym of 

 the latter. Note that the figures of Sp. undula and Bacillus 

 suhtilis in Strasburger's Botany (Eng. ed., p. 333, f. 252g? and 

 f.2546) are entirely different from those given by Cohn, I.e., which, 

 the writer says, " must furnish the basis for all future nomen- 

 clature." 



[OSCILLATORIA AMPHIBIA Ag.] 



Fila glabra, diam. 1-3 /x, dilutissime caerulea pa^ne hyalina, 

 granulis sparsis primum hyalinis, deinde nigrescentibus impleta. 

 Lismore (18, 27), Casino (14). Plentiful in (18). 



Var. MAJOR, n.var. 

 Diam. 4/x. Lismore (18), cum priori multo rarius 



'4 R y 



ii/ 



/ 





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