*26'2 ALGiE. 



89. Corynephora. Frond carnoso-coriaceous, hollow, form- 

 ed of filaments issuing from a central point. 



90. Myrionema. Frond minute, gelatinous, parasitical 

 composed of short, erect, clavate, simple filaments " fixed at 

 their base to a thin expansion." Grev. 



Tribe XX. Rivularie.e. Plants more or less globose, never 

 filiform, carnose, composed of continuous filaments cumulated 

 within. 



91. Rivularia. — Character the same as that of the Family. 



Tribe XXI. Nostochine^e. Plants more or less globose, gela- 

 tinous or carnose, including granules scattered through the mass 

 or ai ranged in nwniliform series. 



92. Protococots. Globules aggregated, naked, filled with 

 granules, seated on a hyaline jelly. 



93. HvEMATOCoccus. Minute gelatinous fronds, aggregated 

 into a frustulose crust and including scattered granules. 



94. Palm ella. A polymorphous gelatine, filled with dis- 

 tinct globular or elliptic granules. 



95. Echinella. Minute gelatinous fron ds, filled with ellip- 

 tical corpuscules, radiating from a centre. 



96. Nostoc. A gelatinous polymorphous frond, filled with 

 crisped moniliform filaments. 



APPENDIX. 



97. Schythymenia. A tough, coriaceous, spreading^/rora.?, 

 composed of fibres intermixed with granides. 



Div. IV. DIATOMACE.E. 1 



■ 



Granules (frustula) of various forms, plane or compressed, more 

 or less hyaline or transparent, rigid and fragile, in parallel series 

 or circles, free, vahed, or imbedded in a mucous mass or gelatinous 



frond, at length separating into definite segments. Small, often very 

 minute plants, in the sea or in fresh-water, mostly parasitic or 



forming floating masses, or mixed with other aquatic vegetables. 



Tribe XXII. Desmidie^e. Filaments cylindrical or angidar, at 

 length separating into segments (^frustula). 



98. Meloseira. Frustula forming simple pseudo-articulat- 

 ed filaments, constricted at the articulations, fragile, easily se- 

 parating. 



1 By Dr. Greville. 



