84 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
2. Diploschistes gypsaceus (Ach.). 
Urceolaria gypsacea Ach. Lich. Univ. 338. 1810. 
Thallus cretaceous white, pulverulent. Differs from D. scrwposus in having some- 
‘what larger spores and mainly in the absence of amyloid reaction of the medulla with 
iodine. 
On dry sterile clay soil near Elsinore and on Santa Catalina Island. 
3. Diploschistes actinostomus (Pers.) Zahlbr. in Engl. & Prantl, Nat. Pflanzen- 
fam. 1!*: 122. 1907. 
Verrucaria actinostoma Pers.; Ach. Lich. Univ. 288. 1810. 
Thallus indeterminate, areolate-rimose to diffract, light to dark ash gray, the areoles 
becoming verrucose, containing one to several apothecia, KHO—; with iodine the 
medulla blue; apothecia immersed, flattish to subglobose, small, the proper margin 
brown to darker, finely radiate-striate; epithecium continuous to subcontinuous, 
grayish brown; thecium colorless, about 140 » high, staining yellow with iodine; 
paraphyses slender, intricate, not septate nor branched, slightly clavate at the apices; 
hypothecium colorless; asci cylindric; spores roundish and obovoid, light grayish blue 
becoming brown, muriform with 3 or 4 transverse septa and 1 or 2 in the long spore 
axis, 18 to 27 » long, 10 to 18 » thick. 
On various rocks in the Santa Monica Mountains; Santa Cruz Peninsula, Herre. 
LECIDEACEAE. 
Thallus crustaceous, ranging from uniform to variously lobed, and to squamulose 
or rimose, rarely approaching the fruticose form; gonidia of the thallus bright green, 
belonging to the genus Protococcus; apothecia generally sessile, surrounded by a 
proper margin, this, like the hypothecium, pallid and waxy or dark (black) and 
horny, containing no gonidia, the thalline margin absent; asci containing from 1 to 8, 
rarely more, spores, these colorless or colored, entire or variously septate; spermatia 
ellipsoid or stafi-shaped. 
KEY TO GENERA. 
Thallus crustaceous. 
Paraphyses not branched, strict, coherent or distinct. 
Spores simple, colorless............2..00 ccc cece eee Lecrpea (p. 34), 
Spores compound. 
Spores 2-celled (bilocular)............2.22.2..... CATILLARIA (p. 48). 
Spores parallel 4 celled to pluricellular, thin- 
walled, the cells (loculi) cylindric......... Bacrpra (p. 50). 
Paraphyses branched, lax; spores 2-celled or muriform- 
multicellular, decolorate to dark .................. RarzocarPon (p. 55), 
Thallus verrucose, squamulose, or microphylline............. TONINIA (p. 53), 
LECIDEA Ach. 
Thallus effigurate or uniform; apothecia circular or when crowded varying to angular, 
flexuose or even oblong, sessile or subsessile; proper margin and hypothecium from 
pallid and waxy to dark and horny; disk pale to black; paraphyses not branched; 
spores 8, rarely more, colorless, simple, globular, ovoid or oblong, thin-walled; sper- 
matia staff-shaped or acicular, straight or curved. 
KEY TO SECTIONS, 
Thallus uniform. 
Apothecial margin and hypothecium brittle, dark............. 1. EuLecrpga, 
Apothecial margin and hypothecium not brittle, pale or dark... 2. Bravora. 
Thallus not uniform. 
Squamulose to squamose, lobed more or less............-2----- 3. Psora, 
