250 OSCILLATOREiE. 



7. OSCILLATOEIiL PULCHELLA Hass. 



Plate LXX. Fig. 5. 



Char. Filaments thick, straight, brittle, vivid green. Stria 

 closBi very conspicuous. 

 Hah. Bottom of pools near Stocket, Aberdeen: Dr. 

 Dickie. Cheshunt : A. H. H. 



The filaments of this fine species are more robnst than those 

 of O, virescens and the strias closer. The only other described 

 species with which it could be confounded is O. spadicea, 

 which it resembles in the closeness and strength of the strias ; 

 but the filaments in O. pulchella are rather finer and much 

 more brittle. 



8. OSCILLATORIA VIRESCENS Hass. 



Plate LXXI. Fig. 9. 



Char. Stratum terrestrial, of a light ceruginous green colour. 

 Filaments of considerable diameter, pale yelloivish green 

 straight, brittle. Strise subdistant. 

 Hah. Cheshunt, Herts : A. H. H. Between Eiver Head 

 and Chipstead, bankside : Mr. Jenner. 



This would appear to be a distinct as well as a fine species. 

 The filaments are longer than those of O. tenuis, and more- 

 over preserve their diameter in drying. Stride nearly a dia- 

 meter of the filaments apart, conspicuous. 



9. OSCILLATORIA THERMALIS Hass. 



Plate LXXII. Fig. 3. 



Char. Filaments small, green. Stria) straight, brittle, sub- 

 distant, very evident. 



Hab. In a stream of hot water, Stevenston : Rev. D. 

 La ndsboro ugh . 



The filaments of this species are as slender as those of O. 



