MARINE ALGJE OF BEAUFORT, N. C. 417 



In addition to the species described above, members of the Myxophyceae were 

 observed in more or less abundance at Marshallburg, N. C. ; Southport, N. C. ; George- 

 town, S. C. ; and Tybee, Ga. ; but the material from these places proved indeterminable 

 or, for various reasons, has not been determined. 



Division II. CHLOROPHYCE> (Kuetzing, in part) Wittrock. 



Chlorospermeae, in part, Harvey, 1858. 

 Zoosporeae, in part, Farlow, 1882. 

 Oosporese, in part, Farlow, 1882. 



GREEN A.LGJB. 



Algae chlorophyll green (rarely red, yellowish, or brownish, sometimes grayish from 

 deposits of lime), containing pure chlorophyll in their cells (rarely mixed with other 

 pigments) ; chlorophyll confined to definitely limited bodies, the chloroplasts. Thallus 

 consisting of one or more cells, simple or branched, filiform or of various shapes, fila- 

 mentous, membranaceous, or tubular. Multiplication asexual or sexual: asexual 

 (propagation) by the fragmentation of the entire plant or of some part, or by noncopu- 

 lating motile cells (zoogonidia, zoospores, swarm spores), or by resting cells (akinetes, 

 aplanospores) ; sexual (reproduction) by at least eventually nonmotile zygotes (zygospores, 

 oospores) formed by the copulation or conjugation of gametes free of membranes; 

 gametes similar (isogametes) , or different in form, size, etc., that is, male and female 

 (heterogametes) , motile or nonmotile. 



The members of this group live mostly in water, either salt or fresh, while some 

 occur on moist soil and some are endophytic. The akinetes and aplanospores are formed 

 from vegetative cells. Zoospores are formed either from ordinary vegetative cells or 

 from special cells, zoosporangia; they are pear-shaped, bear two or four, less often one 

 or many, cilia on their anterior, pointed, colorless end, and often have a red eyespot and 

 contractile vacuole; they come to rest after a longer or shorter time, develop a mem- 

 brane, and usually develop immediately into new plants. Zygotes are formed in one of 

 three ways: (i) By the copulation of two motile gametes, exactly alike or differing 

 slightly in size; (2) by the fertilization of a large nonmotile female gamete (egg) by a 

 small motile male gamete (sperm); (3) by the copulation or conjugation of two non- 

 motile gametes similar in .appearance. The similar gametes are formed from ordinary 

 cells; eggs and sperms are developed in special organs, oogonia and antheridia. The 

 zygote, in some cases, develops immediately into a new plant, but in the majority of 

 forms, after a period of rest, develops swarm spores, which, after swimming about, come 

 to rest and grow into new plants. 



There is no other group of algae about which there is so much difference of opinion 

 concerning the classification. The name Chlorophyceae is here used in a broad sense, 

 including the Heterokontae, Stephanokontae, Conjugatae, etc., of other authors. There 

 seems to be need for a name covering this assemblage of forms which stem to show more 

 or less close relationship to each other. For these it has seemed desirable to retain the 

 old, inclusive name, at least until some uniformity of opinion can be reached regarding 

 their division. In this scheme the divisions of other authors (Conjugatae, Heterokontae, 

 etc.) would be subdivisions under Chlorophyceae. 



Nearly 3,000 species; throughout the world. 



