478 Evans: THREE SOUTH AMERICAN SPECIES OF ASTERELLA 
24 4; pores elevated, measuring (with their surrounding cells) 
mostly 100-120 » long and 70-100 uw wide, surrounded by seven 
or eight ‘(rarely six or nine) radiating series of cells with three 
(rarely four or two) cells in each series, radial walls more or less 
thickened; cells containing oil bodies as in A. elegans; green tissue 
compact, the air chambers narrow, in three or four layers in the 
median portion of the thallus, those of the dorsal layer abundantly 
subdivided by vertical supplementary partitions not reaching the 
epidermis in the vicinity of the pores; compact tissue occupying - 
little more than half the thickness of the thallus in the median 
portion, thinning out rather abruptly in the sides and extending 
about halfway to the margin, composed of cells with slightly 
thickened, pitted walls; mycorrhiza not observed; ventral scales 
ovate to lunulate, pigmented throughout with a reddish purple or 
with more or less bleached appendages, cells containing oil- 
bodies numerous, mostly thirty to sixty, usually scattered but 
sometimes in pairs or small clusters, tending to be more numerous 
scarcely or not at all constricted at the base, mostly 0.7-1.3 mm. 
long and 0.3-0.35 mm. wide, margin entire or vaguely crenulate 
or denticulate from projecting cells, acuminate or abruptly api- 
culate or cuspidate, often tipped with a filament variable in length 
and variously curved, hooked or contorted, the cells very irregular 
usually including several with oil-bodies, averaging in the median 
portion about 70 x 30 yw: inflorescence autoicous: male inflorescence 
borne on a short and slightly expanded ventral branch, the anthe- 
ridia forming an irregular median cluster without marginal paleae 
(so far as observed), ostioles low; female inflorescence borne on 
a slightly longer and more expanded ventral branch; peduncle 
more or less pigmented with purple, 1-2 cm. long when well de- 
veloped, bearing a loose cluster of filiform paleae at the apex 
and scattered paleae elsewhere; disc of receptacle about 4 mm. 
wide, bluntly conical, more or less purple, shortly four-lobed, the 
lobes extending obliquely outward, surface bearing very low and 
coarse tubercles, especially on the lobes, giving the latter a crenate 
appearance, involucre not examined; pseudoperianth more or less 
splotched with purple, mostly eight- to ten-cleft, the divisions 
subulate, loosely connate at the apex and apparently becoming — 
free at maturity: capsule wall not examined; spores brown OF 
yellowish brown, mostly 90-110 » in diameter, with wavy, ™- 
nutely crenulate wings 12-14 u wide along the edges, spherical face 
covered over with a coarse and fairly regular network, the m 
mostly 16-20 pu across, formed by a series of anastomosing ridges 

