ОЧОР ү какав по. 
алы ee ee ee a ады 
RICcIA 15 
Scales па Мрав margin ог rarely slightly exceeding it at thallus-apex 
Sca lackish-purple ; thallus-segments 1-1.5 mm. wide; an theridial 
pee scarcely or not at all elevated. 8. R. nigrella. 
Scales brown or nearly colorless, usually inconspicuous ; thallus-segments 
222 mm. (mostly 1.5-2 mm.) wide; antheridial ostioles prominent, 
onico-cylindrical. 7. R. Campbelliana. 
Scales hardly distinguishable unless at thallus-apex, whitish or hyaline ; 
thallus-segments mostly 1-2 mm. wide; ostioles elevated about .08 
merely punctate or marked with numerous low mostly free ridges. 
5. А. minima. 
"Thallus ciliate on margins or at apex. 
Thallus-segments .75-1.5 mm. (mostly І mm.) wide, the margins densely 
ciliate ; 1-12 cilia, with rare exceptions, springing from the dorsal epidermis 
above decks capsule ; spores soon black and very ent 90-120 и in maxi- 
um diameter. . trichocarpa. 
тылының 1-2 mm. wide, bearing few or numerous Libor cilia on mar- 
gins toward apex but none on dorsal surface; antheridial ostioles not ele- 
vated; spores brown, 70-90 и in maximum diameter, res of con 
face 6-10 и in width. 3. №. Сай 5. 
Thallus-segments 2-2.5 mm. wide, the margins А а few short stout 
cilia ; ostioles conico-cylindrical, .1-.2 mm. high ; spores * 90-118 м in maxi- 
diameter. . К. Lescuriana. 
Thallus 1 sexe on margins and underneath or with very арынын scales, very 
rarely with rudimentary cilia toward apex ; antheridial ostioles conico-cylindrical ; 
plane-faces of the spores reticulate-areolate, meshes of the convex face 10-1 54 
in width. 
. gla ~ 
"Thallus with large air-chambers which finally communicate заветине with the dor- 
urface, giving thallus a spongiose or vesiculose-alveolate appearance. 
Thallus light-green, rather loosely attached to the soil, very thin, the transverse 
sections at least six times broader than high; spores 90-108 и in maximu: 
with a margin 4-10 и 9. R. Catalinae. 
Thallus d yellowish-green, very as osely adherent to the soil, transverse sections 
of the segments 2.5-4 times broader than high; spores 60-00 in maximum 
diameter, with a narrow (sometimes almost deficient) margin 3-5 и in width. 
то. AR. crystallina. 
т. Кіссіл Lescurtana Aust. Proc. Acad. Nat. Sci. Philad. 1869: 
232. 1869. 
Thallus light green and reticulate above, concolorous below, 
or tinged with purple at margins, orbic ular or semiorbicular in 
general outline; the principal divisions few, with a wide-angled 
(3% 30° 909) dichotomy 1-3 times repeated or subcruciately lobed, 
6-10 mm. x 2-2.5 mm., mostly linear-obcuneate, the shorter 
sometimes nearly obcordate ; terminal segments ovate-elliptical to 
* See remarks on the size of the spores of the Californian A. Lescuriana, 
= 
