28 CALTFORiVIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Synopsis.— Yrond both prostrate and erect. Prostrate frond creeping, 

 irregularly expanded and membranous, sometimes a rounded expansion, 

 sometimes irregularly branched or lobed; with rhizoids; without midrib, 

 nerves or veins; margin entire, sinuous, or somewhat lobed. 



Erect frond slightly stalked, flat and linear, with distinct midrib; simple 

 below, subdichotomously or subpalmately segmented, not proliferating; mar- 

 gin sinuous, toothed or incised. Segments decidedly bullose, usually obtusely 

 lobed, with sinuous or toothed margin. Stalk short, linear, flat, occasionally 

 becoming thickened. Midrib well developed, rather wide, frequently 

 branched, soon evanescent. 



Sporangia formed in large, irregularly oblong, frequently lobed or confluent 

 sori, transversely placed upon the segments of the frond. Antheridia as yet 

 unobserved. Cystocarps few, large, conspicuous, scattered over both 

 surfaces. 



Remarks on the Species. — In the fresh state JV. multi- 

 lobum is a dark red to dull carmine, becoming a burnt car- 

 mine to blackish red when dried. The plant is a dwarf 

 one, rarely reaching a height of 9 cm. 



The predominant characters of N. multilohiim are seen 

 in the rather prominent development of the midrib, in the 

 bullose aspect of the frond, and in the peculiar transverse 

 sori. The first named structure is confined to the lower 

 portion of the frond, where it is visible as a definite thick- 

 ening of the median part, though it does not project promi- 

 nently above the surface. At its upper extremity it fre- 

 quently branches, and the resulting portions evanesce very 

 soon into the ordinary tissue of the frond. The bullose 

 frond of N. multilohum is an important feature in the 

 appearance of the tetrasporic plant. Usually the surface of 

 the segments which form the upper portion of the plant 

 exhibits this trait. Here the surface is alternately raised and 

 depressed, while the margin becomes crinkled and lobed. 

 The sori, together with the bullose aspect, furnish the most 

 certain means of identifying the species. No other plant 

 of the coast possesses such a characteristic feature as these 

 transverse sori, usually produced in great abundance on the 

 segments of the frond. 



The characteristic transverse sori serve to distinguish N. 

 niultilobum from N. harveyanum, with which this plant other- 

 wise has several points in common. In N. hai'veyanttm, 

 however, the sori form flabellate lines on the segments of 



