APPENDIX. 371 



6. Pilobolus. Peridiole globular, separating like a cap 

 from the short stalk of a single cell, attached on a uni- 

 cellular ramified mycelium ; columella conical ; spores 

 numerous, free in the peridiole. 



7. Syzygit.es. Filaments erect, simple, branched above, 

 branches and branchlets di- or tri-chotomous, fertile 

 branches forcipate, bearing pairs of opposite internal cla- 

 vate branches which subsequently coalesce. 



8. Eurotium. Peridiole cellular, membranous, sessile, 

 at length bursting irregularly ; spores produced by a cen- 

 tral cellular nucleus, which breaks up into numerous pa- 

 rent cells (asci), in which four to eight minute spores are 

 formed, and finally set free ; filaments of mycelium ra- 

 diating from the base of the peridiole. 



ALG^E SEAWEEDS, ETC. 



Order I. RHODOSPERMEJE or FLORIDE^E Thal- 

 lus leaflike or filamentous, rose-red or purple. Fructifi- 

 cation consisting of: 1. Spores, mostly inclosed in concep- 

 tacles (ceramidia, coccidia, favellidia, etc.). 2. Tetraspores, 

 red or purple (a membranous sac containing, when ripe, 

 four spores). 3. Antheridia (pellucid sacs filled with 

 yellow corpuscles or spermatozoids). 



Families I. RHODOMELACEJE. Frond cellular, areolated 

 or articulated. Ceramidia external. Tetrapores in rows, 

 immersed in ramuli or contained in proper receptacles 

 (stichidia). 



1. Odonthalia. Frond flattened, linear, with obsolete 

 midrib, pinnatifid, alternately inciso-dentate. 



0. dentata. Color, wine-red. 



2. Ehodomela. Frond cylindric, inarticulate, opaque. 

 Tetraspores in podlike receptacles (stichidia). 



R. lycopodioides. Purplish-brown. 

 R. subfusca. Brownish or reddish. 



3. Bostrychia. Frond cylindric, inarticulate, dotted. 

 The surface-cells quadrate. Tetraspores in terminal pods. 



