APPENDIX. 377 



purple ; oval spores in sori, and tetraspores (square) scat- 

 tered over frond. 



2. Bangia. Frond filiform, tubular, composed of radiat- 

 ing cells in transverse rows, in continuous hyaline sheath. 



Order II. MELANOSPORE^E or FUCOIDEJE. Ma- 

 rine. Thallus leaflike, or cordlike, or filamentous. Olive- 

 green or brown. Fructification varied. 1. In Fucaceee, mo- 

 noecious or dioecious conceptacles containing sporanges and 

 antheridia; the spores being fertilized by spermatozoids 

 after discharge of both from the parent. 2. In Lamina- 

 riacese, etc., of collections of clavate or filiform sporanges 

 producing zoospores, with antheridia-like Fucacese. 3. In 

 Cutleriacese similar. 4. In Dictyotacese three forms re- 

 sembling Floridese ; tetraspores, sporanges containing sim- 

 ple spores, and antheridia. 



Family I. FUCACEJE. Frond leathery or membranous, 

 cellular. Spores and antheridia together or separate in 

 spherical cavities imbedded in the frond. 



* Air-vessels stalked. 



1. Sarpassum. Branches bearing ribbed leaves; air- 

 vessels simple. 



2. Halidrys. Frond linear, pinnate, leafless ; air-ves- 

 sels divided by transverse partitions. 



* * Air-vessels immersed in substance of frond, or 

 absent. 



3. Cytoseira. Root scutate. Frond much branched, 

 bushy. Receptacles cellular. 



4. Pycnophycus. Root branching, Frond cy \mdr\Q. Re- 

 ceptacles cellular. 



5. Fucus. Root scutate. Frond dichotomous. Recep- 

 tacles filled with mucus, traversed by jointed threads. 



6. Himanthalia. Root scutate. Frond cup-shaped. Re- 

 ceptacles (frondlike) long, strap-shaped, dichoraotously 

 branched. 



