Schizonema.\ ALGiE DIATOMACE/K. 413 



branches divaricated, the ultimate ones patent. Frustula linear-oblong, 

 elongated. 



5. S. obtusum, Grev. (blunt-pointed Schizonema^) ; filaments 

 robust laxly tufted branched, axils of the branches rounded the 

 extremities obtuse, frustula oblong geminate. — Monema obtusum, 

 Grev. Crypt. Fl. t. 302. 



Parasitic on various small marine Algce. Frith of Forth, Dr. Greville, 

 Appin, Capt. Carmichael, Summer. — Tufts one or two inches long, lax, 

 flaccid, green or brownish. Filaments branched in a somewhat fascicu- 

 late manner, robust and scarcely attenuated till near the extremity. 

 Frustula very numerous. This plant exists in Captain Carmichael's 

 collection under the MS. name of Gloionema myriogranum. 



6. S. corymbosum, Ag. (corymbose Schizonema) ; filaments 

 laxly tufted branched, branches divided towards the extremity 

 in a penicillato-corymbose manner. — Ay. Syst. Alg. p. 11, et 

 Conspect. Crit. Diat. p. 21. 



On various small marine Algce, corallines, &c. Devonshire, Mr. 

 Sconce. — Tufts lax, about an inch in length, pale yellowish or reddish- 

 green. Filaments slender, irregularly branched, but generally at inter- 

 vals, in a fasciculate manner, the extremities corymbose. Agardh places 

 this plant among those that require to be more closely investigated. I 

 have seen only a single specimen, and it must be confessed that its 

 appearance has somewhat the character of monstrosity. 



7. S. comokhs, Ag. (tufted Schizonema); filaments in lax 

 tufts capillary branched, branches nearly simple elongated. Ag. 

 Conspect. Crit. Diat. p. 19. — Conferva comoides, Dillw. Conf. 

 t, 27. (not of E. Bot.) 



On rocks in the sea and on various marine Algce. Swansea, il/V. 

 Dillwyn. Devonshire, Mr. Sconce. — Tufts an inch or more in length, 

 composed of numerous, very detieate filaments, of a reddish or olivaceous 

 green colour. I have not seen this plant in a recent state. It is cer- 

 tainly distinct from the following. 



8. S. Grevillii, Ag. (Grcville's Schizonema); filaments aggre- 

 gated capillary irregularly branched attenuated, frustula scat- 

 tered oblong geminate. — Ag, QoMpeCt. Crit. Diat. p. \\). — Mo- 

 vefile comoide*, Grev. ( '>'///>/. 11. t. o58. 



On rocks in the sea; more rarely on the wood-work of piers, ccc.and 

 on other Algce. sidinouth, Dr. GrevUie, Spring and Bummer. — Plant 

 spreading widely over the smooth surface of rocks, especially where 

 tliere is a slight coating of mud. Filaments very flaccid, about an inch 



in length ; the branches BTen off at a very acute angle, remote or sooso- 



what fosCICUlatC towards the extremity. Fmslulo cylindrical, oblong. 

 The colour when recent is reddish-brown, when dry, grayish or yellow- 

 ish-green. I dare not pronounce this to be the Cotifcrnt 0SSMSJI 

 English Botany, which is a plant I cannot understand from the unsatis- 

 factory figure published in that work. 



\). S. Smii/iii, Ag. | Smith's Schizont mil); filament- (lifted 

 gelatinous irregularly branched, branches spreading acute, frus- 

 tula oblong in numerous parallel leriet geminate at 1. 



