9G 



phylls (Trans. Conn. Acad., voi. 9, p. 347, 1893) and the proper 

 systematic position of the genus in its vcry close relationship to 

 Alaria and its, remoter afjFìnity with Ecklonia, as well as its ahsolute 

 separation from Lessonia. The adult plant was tirst described and 

 figured by Mac Millan (Minnesota Botan. Studies, 2d. ser., pp. 753 

 et seq., especially p. 729 and pi. 5cj and 60, 1902), who, however, 

 states that - « the sorai patches occur upon the lateral pinnae and 

 not upon the mid-lamina » (loc. cit., p. 738;. 



The fruiting plants of Pterygophora are undoubtedly common 

 at the proper season of the year which is about midwinter. 1 had, 

 up to the time of the publication of Mac Millan' s paper, paid no 

 attention to the matter, but in November of 1906, I examined a 

 very considerable number of plants cast ashore from Duxbury Reef, 

 in Marin County, California, near the village of Bolinas. These sho- 

 wed sori, of advanced development in evcry case and their study 

 makes necessary some changes in the statements of Mac Millan. 

 He says that the sorai patches on the lateral pinnae « form some- 

 what irregular patches on both surfaces of the pinna and much of 

 its area fails to develop them ». From this, it might seem that Mac 

 Millan' s plant or plants, were just beginning to form the sori. In 

 ali the specimens examined by me, the sori are regular bands, often 

 lobed somewhat irregularly above, but uniform below the tip and 

 covering the surface of the pinna as to width with the exception 

 of a very narro w sterile margin, a point in common with Alaria. 

 The lower end of the sorus is uniformly regular and rounded. As 

 to the greater part of the area of the pinna failing to develop sorai 

 patches, that certainly must be a matter of age. In specimens exa- 

 mined by me, as much as threequarters of a long pinna is covered 

 by the regularly shaped sori and the length of the whole sorai area 

 is about 40 cm. As the formation of sorus proceeded as the pinna 

 continued to grow and wore away at the tip, it seemed that it might 

 possibly come about that the whole of the pinna might be covered 

 on both surfaces with continuous sorai tissue. I did not, however, 

 see any specimen in which such was the case, although in some 

 of the shorter pinnae most of the surface-area was covered. The 

 fruiting pinna of Pterygophora bears an exccedingly close resem- 

 blance to one the few first pinnae to fruit on most species of Alaria. 



