250 OSCILLATORE^. 



7. OSCILLATORIA TULCHELLA Hass. 



Plate LXX. Fig. 5. 



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

 close, very conspicuous. 

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

 Dickie. Cheshunt : A. H. H. 



The filaments of this fine species are more robust than those 

 of O, virescens and the stria3 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 LXXL Fig. 9. 



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

 Filaments of considerahle diameter, pale yellowish green 

 straight, brittle. Stride subdistant. 



Hab. Cheshunt, Herts : A. H. H. Between Elver 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. Striae nearly a dia- 

 meter of the filaments apart, conspicuous. 



9. OsCILLATORIA THERMALIS HaSS. 



Plate LXXII. Fig. 3. 



Char. Filaments small, green. Striae straight, brittle, sub- 

 distant, very evident. 



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

 Landsborough. 



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



