422 BULLETIN OF THE B.UREAU OF FISHERIES. 



Many forms of the species approach closely in appearance to U. fasciata and slightly to Entero- 

 morpha lima. 

 3. Ulva fasciata Delile. 



Ulna fasciata. Delile, 1813, p. 153. Pi- 58, f. 5- 

 Ulva fasciata, Harvey, 1858, p. 58. 

 Uha fasciata, De Toni, 1889, p. 114. 

 Uha fasciata, Collins, 1909, p. 216. 

 P. B. A. No. 221. 



Frond divided into more or less linear segments, margin smooth or undulate ; in cross section the 

 two layers of cells separate somewhat at the margin, which is rounded, with a small open space between 

 the rows. 



Florida; West Indies; California; warm waters all over the world. 



Abundant in warm water of tide pool, northwest corner of " Town Marsh, " Beaufort, N. C., resting 

 on the bottom, summer. 



A variable species varying from forms with a central axis and lateral lobes (as in a pinnately com- 

 pound leaf) to forms having almost a continuous sheet with lobes few and inconspicuous, sometimes 

 dichotomous; frond more or less perforate; lobes 5 mm. to 5 cm. in width; margin smooth and even or 

 much crisped and undulate. (In this last form it corresponds to forms of Enteromorpha lima.) The 

 structure of the frond is similar to that of U. lactuca, except the margin, which resembles E. lima. On 

 the California coast it is hard to draw the line between this species and U. lactuca, either from the shape 

 of the frond or from its structure. Four forms have been distinguished there, passing into each other 

 more or less. 



At Beaufort the species is easily distinguished by the much-crisped, lobed thallus with decidedly 

 undulate margins, and by the structure of the frond at the margins. It forms sheets of considerable 

 extent, with lobes long or short, broad or narrow, much crisped and much perforate. No specimens have 

 been found with decidedly pinnate lobes like some of those occurring on the California coast. Some 

 specimens approach forma lobata (P. B.-A. No. 863), but are more crisped and ruffled. Many lobes are 

 long and narrow and much ruffled, resembling forma tcsniata (P. B.-A. No. 862). The species has been 

 observed at Beaufort only in summer; its condition at other times of the year is unknown. This is the 

 most northern station reported for the species on our Atlantic coast, and is probably its northern limit. 



Family 2. CFUETOPHORACELC Wille. 



Ulotrichiacese, De Toni, 1889, p. 151 (in part). 



Fronds filamentous, except in a few doubtful forms, usually much branched, some- 

 times united in disklike expansions; cells uninucleate, with band-shaped or disk-shaped 

 chromatophore, often somewhat divided or wijh projections; with one, rarely more 

 pyrenoids; hairs almost always present, but vaiying in character; asexual propagation 

 by four ciliate, in some cases biciliate, zoospores, by aplanospores, akinetes, and with 

 special Palmella and Schizomeris stages in many genera; sexual reproduction in many 

 genera by gametes, similar to the zoospores. 



About 150 species, mostly fresh water, some marine, few aerial, etc., throughout the 

 world. 



A family of doubtful limits, being differently defined by nearly every author. The 

 present treatment follows that of Collins (1909). The methods of reproduction seem to 

 vary in different members, but are imperfectly known in the majority of cases. 



KEY TO GENERA. 



Thallus in cell wall of algae x . Endoderma (p. 423). 



Thallus on shells, stones, etc 2. Ulvella (p. 423). 



