32 RICCIACEAE 
air-chambers ph epidermis (in dried material) disorganized and 
indistinct : monoicous: ostiolar elevations prominent, cylindrical, 
.15—.27 mm. x pope mm.: capsules rather deeply immersed, 
scarcely prominent even. at maturity; spores soon dark-brown, 
becoming nearly opaque, 60-90 и maximum diameter, distinctly 
angular, with a narrow, granulate-papillate, sometimes almost de- 
ficient, margin (mostly 3-5 м broad), the convex face with strong 
anastomose-reticulate ridges, about 7 or 8 imperfectly formed 
areolae measuring its diameter, those near the middle usually 
larger (15—30 и) and sometimes enclosing a free-ending spur, the 
plane faces marked with short free or irregularly anastomosin 
ridges, the mature more opaque spores appearing tuberculate- 
papillate. 
On the banks of а stream upon a rocky hillside, southern 
slope of the Dixey Mts., Lassen Co. (M. S. Baker and F. P. 
Nutting, July 2, 1894). We refer here also a specimen in herb. 
Underwood, collected near San Francisco by Mrs. Katharine 
Brandegee in 1802, which, in the more solid—less conspicuously | 
vesiculose-alveolate—thallus, approaches the closely allied Ж. 
Brandegei (from the southern extremity of the peninsula of Lower 
California). 
The Lassen County plant seems scarcely to differ from 
European specimens of R. crystallina unless possibly in the greater 
opacity of the spores when fully mature and in their somewhat 
narrower margin. 
Riccia crystallina is listed in Dr. Bolander's “ Catalogue of the 
Plants growing in the Vicinity of San Francisco." 
Riccià Евозти Aust. (Bull. Torr. Bot. Club, 6: 17. 1875), orig- 
inally described from Nevada and Colorado, and since found to be 
quite widely distributed in the Rocky Mountain region and to extend 
as far easward as the Mississippi Valley is to be expected in Cali 
fornia. It can readily be distinguished from any ofthe Californian 
species here described by the small narrowly margined spores, 45-58 
и in maximum diameter, marked almost uniformly over the en- 
tire surface by numerous short, delicate, wavy ridges which rarely an- 
astomose ; the thallus, which is thin in texture, with a fibrous-reticu- | 
late and minutely foveolate surface, becoming lacunose and spongy in > 
the older parts, forms flat, dark- or grayish-green rosettes, 8-15 mm. in | : 
diameter, closely adherent to the soil, with numerous narrow usually 
crowded divisions .5-1.5 mm. wide; the covering of the abundant 
