162 University of California Publications in Botany [Vol. 8 



also, as to how many varieties or even species are to be properly 

 referred under it. The illustrations by Kuetzing (1856) both under 

 B. plumosa (pi. 83, f. I) and under B. abietina (p. 80, f. I) are 

 usually referred to B. plumosa. On comparing these illustrations with 

 those of Harvey (1846, pi. 3), Greville (1830, pi. 19) and of 

 Bryopsis Lyngtyei Hornemann (1818, pi. 1603) and its reproduction 

 by Lyngbye (1819, pi. 19, f. B), it seems evident that there is con- 

 siderable variety among the European plants referred to B. plumosa. 

 Unfortunately the figure of B. arhuscula Lamouroux (1809, pi. 5, f. 1) 

 is only of the habit of the plant. 



Without opportunity of examining a distinct type, or any speci- 

 mens from the type locality, it is impossible to determine with any 

 certainty just what the Ulva plumosa Hudson may be. However, 

 judging by specimens from Debray from the neighboring coast of 

 France, it seems likely to prove to be a plant very similar to that 

 figured by Kuetzing (1856, pi. 83, f. II), viz., a distichous plant 

 with pinnules gradually tapering to both base and apex. This grad- 

 ually tapering base of the pinnule is not found in any of our speci- 

 mens of B. corticulans or B. hypnoides. It may possibly be that this 

 is characteristic of only younger stages of the European plant, but this 

 does not seem likely. An illustration which seems to be reasonably 

 authoritative, and one that may serve as a basis for discussion is that 

 of Ulva plumosa of the English Botany (vol. 33, 1814, pi. 2375). 

 This seems also to be the basis for the figures of plate 19 of Greville 's 

 Algae Britannicae (1830). The agreement of these figures with that 

 of Kuetzing is very close. 



As to whether Bryopsis plumosa is represented on the Pacific coast 

 of North America, or not, there is little to be said. The name appears 

 in certain local lists and Tilden (Amer. Alg., no. 371) has distributed 

 a plant from Tracyton, Washington, in the Puget Sound region which 

 seems rather to be B. corticulans Setchell. There is a single specimen 

 collected by Miss Hurd (Herb. Univ. Calif., no. 200726) which seems 

 to agree fairly closely with the illustration in the "English Botany" 

 and we refer this to B. plumosa with some hesitation. The shape of 

 the pinnules seems to be fairly characteristic. In this specimen the 

 bases of the lower branches show several short, blunt lobes. Older 

 specimens might show that these grow out into short rhizoids such 

 as are found abundantly in Atlantic Coast and European plants 

 referred to this species. The description given above was drawn up 

 with especial reference to our plant. 



