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University of California Piihlic-ations in Botany [Vol.8 



This species is one of the truly marine species, the type locality 

 being Porto Maurizio in Liguria on the northwestern coast of Italy. 

 The plants from Alameda, on San Francisco Bay, formed a layer on 

 the wall of the buttress of a bridge. In habit, diameter of trichomes, 

 and proportion of cells our plant corresponds with Gomont's descrip- 

 tion. The trichomes, however, are not so gradually attenuated, not 

 quite so capitate, and not quite so constricted at the dissepiments as 

 Gomont's figure indicates. In the absence of opportunity of con- 

 sulting either the type or an authentic specimen, it seems best to 

 refer our specimens provisionally to this species. 



18. Lyngbya Ag. 



Filaments with a sheath, simple, either free or aggregated into 

 dense, floccose, caespitose or pannose masses, attached or free-float- 

 ing; sheath thin and homogeneous or thick and at times lamellate, 

 either hyaline or of a sordid j'ellow or brown color ; trichome not con- 

 stricted at the dissepiments, not tapering, or only slightly so at the 

 apex, terminal cell wall often thickened. 



Agardh, Sj'st. Alg., 1824, p. xxv. 



The genus Lynghya is usually given as having been described by 

 C. A. Agardh in 1824 (Syst. Alg., p. xxv, p. 73), but Pfeiffer (1874, 

 p. 184) gives the date 1820, viz., the Aphorismi botanici (p. 98). The 

 name Lynghya is given in the Aphorismi (D. VII, p. 98) as contain- 

 ing thirteen species but without description or synonymy. Pfeiffer 

 also refers with doubt to C. A. Agardh 's Species Algarum, I, giving 

 the date as 1820 and not quoting a page number. The Species Algarum 

 is dated 1820 to 1828, and in no part of it do we find reference to 

 Lynghya. In 1824 C. A. Agardh referred seven species and three 

 varieties to Lynghya. Of these Gomont identifies four as either 

 wholly or in part Lynghya in the proper sense, four as "species 

 inquirendae, " and the remaining two as wholly made up of other 

 things. As now established, Lynghya contains about sixty species, 

 largely marine. 



Key to the Species. 

 1. Filaments caespitose, fixed (epiphytic) at the center and free at both ends 



(Leibleinia) 2 



1. Filaments not caespitose, free or with attached base (Eulyngbya) 4 



2. Filaments spirally twisted about other filamentous algae 



2. L. epiphytica (p 74) 



2. Filaments not spirally twisted 3 



3. Trichomes 5-8/a thick 1. L. gracilis (p 73) 



