BRITISH DIATOMACE^E. 7^ 



from the base, and irregularly submembranous by cohesion above ; 

 ramuli short, obtuse ; frustules very numerous in closely packed 

 files; valves elliptico-lanceolate, acute. Length of frond 1" to 1*5". 

 Length of frustules -0009". Breadth of valve 0002". v.s. 



Ag. Syst. p. 11. Harv. Man. p. 210. ad specim. authen. Micromega ramo- 

 sissimum, Ag. Consp. p. 22. 



Marine. Salcombe, Mrs. Griffiths. Kinghorn, Fife, October 1853, Dr. 

 Greville. Swanage, Dorset, April 1847; Coast of Sussex, March and August 

 1852, W. Sm. 



Plate LIX. 369. 



15. Schizonema laciniatum, Harvey. Frond filiform, much branch- 

 ed ; filaments often cohering into rope-like tufts ; ramuli very long ; 

 frustules numerous, crowded in irregular files ; valves elliptical, 

 somewhat acute. Length of frond l'' to 3". Length of frustule 

 •0013". Breadth of valve -00035". v.v. 



Harv. Man. p. 210. ad specim. authen. 



Marine : on rocks. Torbay, Mrs. Griffiths. Minehead and Isle of Arran, 

 Sept. 1853, Dr. Arnott. Seaford, Sussex, April 1850, W. Sm. Joppa near 

 Edinburgh, Dr. Greville. 



Plate LIX. 370. 



16. Schizonema parasiticum, Harvey. Frond capillary, branched ; 

 filaments slightly cohering above ; ramuli short, patent, mucus 

 often rugose; frustules crowded in files more or less distant; 

 valves elliptico-lanceolate, acute. Length of frond *5" to l". 

 Length of frustule -0011". Breadth of valve "0002". v.v. 



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



Marine : attached to other Algse. Torbay, Mrs. Griffiths. Aberdeen, 

 Dr. Dickie. Cuckmere Harbour, Sussex, April 1852 ; Beachey Head, April 

 1853; Ballycottin Bay, Co. Cork, May 1855, W. Sm. Joppa near Edin- 

 burgh, Dr. Greville. 



Plate LIX. 371. 



17. Schizonema gracillimum, n. sp. Frond capillary, simple be- 

 low, sparingly branched and submembranous towards the apices ; 

 frustules crowded in irregular files ; valves elliptico-lanceolate, 



