390 University of California Publications in Botany [Vol. 6 



mam' different forms have been discovered and described that the 

 limits of these genera have become poorly defined. As I pointed out 

 in a previous paper (1913, p. 327), all of the well-defined species of 

 Cystophora should be placed under the genus Blossevillea according 

 to the Vienna rules governing priority. Blossevillea was created to 

 receive a fairly well-defined group of Fusaceae growing in the south- 

 ern hemisphere. The chief difficulty now remains — to understand 

 and interpret the limits of the genera Cystophyllum and Cystoseira. 

 Harvey points out that the distinction between these two genera lies 

 in the fact that Cystophyllum has the cysts limited to the terminal 

 ramuli, and only the receptacular ramuli lie beyond, terminating the 

 branchlets, while the cj'sts in Cystoseira are not limited to the ter- 

 minal ramuli. Kjellman (in Engler and Prantl) makes use of the 

 same characters in separating the two genera, as has K. Yendo also 

 (1907), but none of these authors have made any attempt to sep- 

 arate, according to the above-mentioned marks of distinction, the 

 thirty-five or more species that are now listed under these two genera. 

 It does not seem to the writer that these characters are of sufficient 

 stability and importance to be made use of as generic distinctions, 

 since one may find both conditions in the same species; and if a 

 revision of the genera based upon them should be made, it would 

 necessitate many transfers, some of which might not be desirable. 

 Cystoseira Osmundacea would become Cystophyllum Osmundaceum 

 because most of the cysts are in the terminal branches. But on 

 account of the fact that some plants have a portion of the earliest 

 formed cysts back among the vegetative branches, one may be justi- 

 fied in permitting the species to remain where it is, although on the 

 border line if the position of the cysts only is taken into consideration. 

 With very rare exceptions the cysts of C. neglecta diagnosed 

 above are in the terminal branches and only the receptacular branches 

 are beyond, which would place it in the genus Cystophyllum, but the 

 general aspect of the species, from the holdfast to the apex, through- 

 out, is so similar to Cystoseira Osmundacea as to leave but little doubt 

 as to its close affinity to that species. This conclusion is further 

 strengthened by the fact that both grow in tlie same general locality. 

 I am unable at present to make a critical revision of these two genera 

 on account of the lack of adequate material for study. There is much 

 need, however, of such a critical study, that a more satisfactory basis 

 for distinction may be established. If such distinction can not be 

 discovered the two genera should be combined. 



