78 BRITISH DIATOMACE^E. 



upwards. Length of frustule -0008" to '0011". Breadth of valve 

 •0002". v.v. 



Var. /3. Filaments dark-coloured, much branched, and very tenacious. 



Ag. Syst. p. 10. ad specim. authen. in herb. Grev. Ag. Consp. p. 20. Grev. 

 B.F. p. 412. Harv. Man. p. 212. ad specim. authen. Kiitz. Bacill. xxvi. 

 3. ad specim. quae dedit cl. De Brebisson. Monema Dillwynii, Grev. 

 S. C. F. tab. 297. Conferva foztida, Dill. Conf. tab. 104. 



Marine : attached to larger Algae. Torbay, Mrs. Griffiths. Near Bristol, 

 July 1845, Mr. Thwaites. Aberdeen, Dr. Dickie. Brodrick Bay, August 1853, 

 Dr. Arnott. Kinghorn, Fife, September 1853, Dr. Greville. North Fleet, 

 Mr. Shadbolt. Poole Bay, December 1847 and June 1849 ; Hove, Sussex, 

 November 1851 ; Seaford, February 1852; Cork Harbour, November 1855, 

 &c, W.Sm. 



A widely distributed species, often occurring in salt-marshes in enormous 

 quantities, and e'asily recognized by its long flaccid tenacious filaments, like 

 tufts of fine chestnut-coloured hair. Var. /3. occurs in running water, and is 

 in no way different from the ordinary form, except in its more profuse ramifi- 

 cations and darker colour ; in mass it is almost black. 



Plate LVIII. 366. 



12. Schizonema implicatum, Harvey. Frond capillary, much 

 branched, entangled, and implicate throughout ; ultimate ramuli 

 long ; frustules irregularly crowded ; V. lanceolate, obtuse. Length 

 of frond 3". Length of frustule -0009" to -0012". Breadth of valve 

 •0003". v.s. 



Harv. Man. p. 213. ad specim. authen. 

 Marine. Salcombe, Mrs. Griffiths. 

 Plate LIX. 367. 



13. Schizonema obtusum, Grev. Frond filiform, sparingly branched; 

 apices abrupt ; frustules exceedingly numerous, in irregular files ; 

 valves elliptical. Length of frond 1". Length of frustule •0011". 

 Breadth of valve -00025". v.s. 



Grev. B. F. p. 413. Harv. Man. p. 209. ad specimina authentica. 



Marine; on larger Algae. Torbay, Mrs. Griffiths. West Coast of Scotland, 

 Dr. Arnott. 



Plate LVIII. 368. 



14. Schizonema raniosissimum, Ag. Frond filiform, much divided 



