MARINE ALG& OF BEAUFORT, N. C. 435 



Stolon usually stout, naked, erect branches flat, linear, obtuse, up to 30 cm. long and 3 cm. wide, 

 rarely divided, margin entire, sometimes slightly undulate, similar branches often arising proliferously 

 from any point on the original branches; color blackish or olive green. 



Florida; West Indies; Yucatan; Atlantic coast of northern Africa; Mediterranean. 



One fragment of an upright branch, Bogue Beach, Beaufort, N. C., April, 1908. 



It seems improbable that the fragment found here grew in this region at this season of the year; it 

 seems much more probable that it was brought here by the Gulf Stream from Florida or the West Indies. 



This is the most northern point reported for the species or the genus. 



Division III. PHyEOPHYCEjE (Thuret) Kjellman. 



Zoosporeae, Farlow, 1882, p. 40 (in part). 

 Oosporeae, Farlow, 1882, p. 98 (in part). 

 Fucoideae, De Toni, 1895, p. i. 



BROWN ALG^. 



Algae olivaceous brown, containing in their cells endochrome composed of chlo- 

 rophyll and a characteristic brown pigment, fucoxanthin; endochrome contained in 

 definite chromatophores ; thallus varying extremely in size and form; cells containing 

 mostly only one nucleus. Multiplication asexual or sexual: asexual (propagation) by 

 motile noncopulating biciliate zoospores, or by aplanospores, or by specialized or non- 

 specialized portions of the thallus; sexual (reproduction) by zygotes formed by the 

 copulation of gametes; gametes similar (isogametes), or different in form, size, etc.- 

 that is, male and female (heterogametes) usually motile, in some families differentiated 

 into large nonmotile eggs and small motile sperms; all motile cells, zoospores or gametes, 

 have two laterally inserted cilia except among the Dictyotaceae where the sperms are 

 monociliate; zoospores, aplanospores, and gametes produced in special organs (sporangia 

 or gametangia) which are borne on ordinary portions of the thallus or on more or less 

 specialized portions; asexual and sexual organs occurring on different individuals or, 

 less often, on the same individual; in some forms, sexual and asexual generations alter- 

 nating with each other in the life cycle; male and female gametes, when present, pro- 

 duced on the same or on different individuals; almost exclusively marine, some endo- 

 phytic, a very few in fresh water. 



About 1,000 species throughout the world, but reaching their greatest development 

 in cold seas. 



KEY TO ORDERS. 



Asexual propagation by biciliate zoospores, rarely by nonmotile aplanospores; sexual repro- 

 duction usually by motile similar or dissimilar gametes, in one family by nonmotile eggs 

 and motile biciliate sperms; sporangia and gametangia occurring on superficial portions of 

 the thallus or arising from the transformation of surface cells i. PH^EOSPORE^E (p. 436). 



Asexual propagation lacking; sexual reproduction by nonmotile eggs and biciliate motile 

 sperms; gametangia arising in sunken conceptacles usually on more or less specialized 

 portions of the thallus 2. CYCLOSPORE^ (p. 449). 



Asexual propagation by nonmotile aplanospores; sexual reproduction by nonmotile eggs 

 and motile monociliate sperms; sporangia and gametangia arising from the transforma- 

 tion of surface cells, occurring singly or in groups, usually on ordinary portions of the 



thallus 3- DlCTYOTAIvES (p. 453). 



