upwards. Length of frustule -0008" to •OOll". 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. Kütz. Bacill. xxvi.
3. ad specim. quæ dedit cl. De Brebisson. Monema DiUwynii, Grev.
S. C. F. tab. 297. Conferva foetida. Dill. Conf. tab. 104.
Marine : attached to larger Algæ. 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 easily 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 ramifications
and darker colour ; iu 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 fru s tu le -0009" t o -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 a b ru p t; frustules exceedingly numerous, in irregular files
valves elliptical. Length of frond 1". Length of frustule -OOll".
Breadth of valve •00025". v.s.
Grev. B. F. p. 413. Harv. Man. p. 209. ad specimina authentica.
Marine; on larger Algae. To-ih&y, Mrs. Griffiths. West Coast of Scotland,
Dr. Arnott.
Plate LVIII. 368.
14. Schizonema ramosissimum, Ag. Frond filiform, much divided
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 fru stu le s-0009". Breadth of v alve-0002". v.s.
Ag. Syst. p. 11. Harv. Mai .
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 aud August
1852, W. Sm.
Plate LIX. 369.
15. Schizonema laciniatum, Harvey. Frond filiform, much branched
; filaments often cohering into rope-like tu fts ; ramuli very lo n g ;
frustules numerous, crowded in irregular files; valves elliptical,
somewhat acute. Length of frond 1" 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 1".
Length offrustule -OOll". Breadth of valve '0002". v.v.
Harv. Man. p. 213. ad specim. authen.
Marine : attached to other Alg®. 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 Edinburgh,
Dr. Greville.
Plate LIX. 371.
17. Schizonema gracillimnm, n. sp. Frond capillary, simple below,
sparingly branched and submembranous towards the apices;
frustules crowded in irregular files; valves elliptico-lanceolate,