A Monograph of the Genus Alaria. IIQ 



. = Alaria prœlonga f. nana Setch. ; in Coll.,' Hold, and Setch. : 

 Phyc. Bor.-Aiiier., No. 1292. 

 = Alaria marginata f. r.ana Collins: Mar. Alg. of Vaiieouv. 

 Island, p. 110. 



Definition of the species. Root, holdfast of dendritic ramifica- 

 tion. Blade linear-lanceolate, 30-50 cm. in length, 6.0-8.5 cm. in 

 breadth, coriaceous, finely striated when 'old, cryptostomata want- 

 ing, margin entire, splitting in the older part of the blade obliquely 

 to the midrib; base of blade acute, tip narrowed above, pinnately 

 cleft and generally roughly worn away. Stipe 4-8 cm. in length, 

 cylindrical at the base, terete or compressed above, measuring 

 4-6 mm. in breadth, and more or less narrowed at the transition 

 point, lower half of the length naked, upper half bearing the sporo- 

 phylls. Midrib smooth, complanated, 5-8 mm. in breadth, elevated 

 above the blade equally on both surfaces with roundish edges, 

 continuous to the stipe below. Sporophylls metasoric, numerous, 

 often 40 or more, obliquely pinnately arranged on both margins 

 of the stipe, a few lower ones at wide intervals, but middle and 

 upper ones approximate and regularly disposed, adding new ones 

 successively upwards, long-cuneate, 6-12 cm. long, 7-25 mm. broad, 

 with more or less well-defined petiole ; base of sporophyll tapering 

 or obtuse, generally asymmetrical ; tip obtuse or truncate, generally 

 irregularly dentated. Sorus, on both surfaces of each sporophyll, 

 in a continuous patch occupying the lower half of the surface with 

 obscure and fading boundary. 



Remarks on the species. The present species has a well-mark- 

 ed character making it readily distinguishable from the others. 

 The sporophylls are always attenuated towards the base to form 

 comparatively long petioles, the lower side being more developed 

 than the upper, resulting in an oblique ascending base. This 



