244 University of Californm Pvhlications in Botany [Vol. 8 



(1840, p. 21) describe the yonnp: specimens as provided witli a short 

 stipe, and Rosenvinge (1893, p. 942, f. 48, 1894, p. 148, f. 48) con- 

 firms this and adds figures of the young plants with stipes which 

 remain tubular. No. 387 of Tilden's American Algae is, in our copy 

 at least, a light colored plant, ])rovided with a distinct tubular stipe 

 about 3 cm. long and 3-4 mm. in diameter (in pressed specimen). 

 This specimen previously referred by us to Ulva Lactuca var. rigida 

 (cf. Setchell and Gardner, 1903, p. 210), has the structure, although 

 not the exact color, of Monostrotiia ficscum. 



Rosenvinge (1893, p. 942, f. 17 C, D, 1894, p. 147, f. 17 C. D) calls 

 attention to the fact that each cell in this species contains two chro- 

 matophores, one at each end, and Jonsson (1904, p. 631) emphasizes 

 this as characteristic of this species in distinction from all other 

 species of Monostroma. Collins (1909, p. 25), however, finds only one 

 chromatophore in fresh material of M. fuscum from Revere Beach, 

 Massachusetts, and also calls attention to Wittrock's figure (1866, 

 pi. 3, f. 11) which he saj^s "shows a perfectly uniform chromatophore 

 quite like that of the Revere Beach plant." We have seen what 

 appear to be two distinct chromatophores in some of our specimens 

 of varieties splendens and Blyttii where the cells are much elongated 

 verticalh^ but have failed to find them in plants seemingly' to be more 

 of the type of the species. 



19. Enteromorpha Link 



Frond persistently tubular, usually slender, but often ample, 

 simple, proliferous or branched, its. wall consistiiig of a single layer 

 of cells, commonly, but not always, arranged parenchymatously ; all 

 the cells of the membrane, except the very lowest, capable of produc- 

 ing zoospores or gametes, which are discharged through an opening 

 in the outer cell wall. 



Link, Epistola, 1820, p. 5. 



The name Enteromorpha has been for so many years practically 

 agreed upon among writers as the name for this genus that there is 

 little need, perhaps, for anticipating any change. The only name 

 which seems strictly and definitely to antedate it is that of Tuhularia 

 of Roussel (Flore du Calvados, ed. II, 1806) which is said to have 

 been founded upon Ulva intestimdis (cf. Desvaux, Journ. Bot., 1813, 

 p. 144). It is not possible for us to verify this reference at present 

 and we follow the weight of authority in retaining Enteromorpha for 

 the accepted generic name. 



