32 University of California Publications in Botany [Vol. 10 



study much more extensively in the same general locality. As reported 

 in Setchell and Gardner (loc. cit.), it was found growing on sand 

 rocks. It is quite common on the sand rock ledges of that vicinity, but 

 I have learned that its normal habitat is farther down in the littoral 

 belt than was first reported. There were but a few plants growing in 

 the first locality mentioned, on a ledge in the upper littoral belt, but 

 in a shaded location. The majority of the specimens were very much 

 dwarfed. The average height in their normal habitat is about 16 cm., 

 although some specimens were found up to 32 cm. high. Gardner, 

 no. 2336a, plate 26, represents a fruiting plant of medium height from 

 this collection. 



Fucus membranaceus sp. nov. 



Frondes magnitudine variabiles parvae vel usque ad 4 dm. altae, 

 manifesto membranaceae, obscure olivaceo-brunneae vel superne 

 luteolae ; segmentis linearibus vel paullo cuneatis, strictis, alis mem- 

 branaceis, costa comparative parva distincta et percursa, crypto- 

 stomatibus sparsis, plerumque ad segmenta terminalia et subterminalia 

 dispositis, comparative parvis in sicco papillosis, receptaculis vulgo 

 complanatis, partim inflatis, bifidis acuminatisque. 



Growing in the littoral belt. From the Bering Sea to Puget Sound. 

 Washington. 



For a discussion of this species nmjor see page 11. 



Fucus membranaceus f. abbreviatus f. nov. 

 Plate 27 



Frondes breves, membranaceae, flabelliformes, decomposite dicho- 

 tomo ramosissimae, 8-14 cm. altae; segmentis strictis, anguste cuneatis 

 vel sublinearibus, 5-9 mm. latis, apice truneatis, costa parum promi- 

 nente paululum evanescente, alis tenuibus cryptostomatibus in seg- 

 mentis terminalibus 20-40 in quoque cm. quadrato, ad partem frondis 

 inferiorem paucis, parvis siccatis evidentioribus ; receptaculis bifidis, 

 plerumque muco inflatis, apice acuminatis aut truneatis, paullo divari- 

 catis distincte definitis; coneeptaculis numerosis, prominentibus. 



Growing on rock ledges exposed to heavy surf, in the upper limit 

 of the littoral belt. Sitka, Alaska. 



Type, Gardner, no. 39956 (Herb. Univ. Calif., no. 201192), July. 

 1917. 



Forma abbreviatus grew on the same islet on which forma acum- 

 inatus was found growing, but mostly higher up, some specimens were 

 even above mean high-tide level. It differs from forma aeuminatus 



