406 PROCEEDINGS OE THE AMERICAN ACADEMY 



laribus sessilibus nigris disco nudo opaco subscabrido intus albo hypo- 

 thecio fusco-nigro imposito mox convexo-protuberante marginemque 

 tenuem subobscurum excludente. Sporte majusculaj, oblongae, atro- 

 fuscescentes, murali-divissB, diam. 3-plo longiores. On trunks of Oaks, 

 Alcatraz, California, Mr. Wright (U. S. N. Pacif. Expl. Exp.). And I 

 possess a fragment of the same Lichen, from trees on the banks of the 

 Columbia, in Oregon Territory, Dr. Newherry. Crust with much of the 

 habit of states of L. disciformis, from similar habitats, but greenish ; 

 and the margins of the protuberant apothecia perhaps more obscure 

 than in that species. The spores are quite different. These are always 

 without dissepiment, showing at first a grumous protoplasm, which, as 

 the spore attains to its maturity and very dark color, assumes a cellu- 

 lar configuration resembling mason-work, as in L. atro-alba, and other 

 species of the same group (^Rhizocarpon, Koerb.). 



Lecidea Africana, sp. nov. : thallo crustaceo adnato radioso-lobato 

 mox squamuloso-areolato, areolis applanatis crenulato-lobatis ambitu ri- 

 moso-multifidis Isevigatis luteis subtus nigris ; apotheciis areolis innato- 

 sessilibus cupularibus nigi'is, margine tenui crenulato-rugosulo flexuoso, 

 disco opaco nudo intus albo demum convexiusculo subexcluso. SporiB 

 ellipsoidea^, apicibus acuta3, 1 - 3-septata3, ati'O-fuscescentes, diam. 1|- - 

 2^-plo longiores. On rocks (friable sandstone) on hills near Simons- 

 town, Cape of Good Hope, Mr. Wright. Thallus in young plants crus- 

 taceous-foliaceous, radiate-lobate ; but the centre passing into mostly 

 flattish, areolate, crenulate squamules, which are somewhat palmate- 

 multifid at the circumference, and black beneath ; bright-yellow, be- 

 coming whitish in some specimens. Apothecia always black ; the 

 slightly tumid or obtusish, wrinkled-crenulate margin at length almost 

 excluded by the convex, naked disk, which is white within and rests 

 upon a black hypothecium. Spores smallish, ellipsoid, with rather 

 acute tips, the at first simple protoplasm dividing into two round spo- 

 roblasts, and crossed by a central dissepiment ; the sporoblasts then 

 divided, and the spore appearing twice or thrice septate, according 

 as the central dissepiment is more or less apparent ; finally blackish- 

 brown, and the dissepiments more or less obscure. The Lichen has, 

 at first sight, a good deal of resemblance to L. geographica, (as Moug. 

 & Nestl. Cr. Vog. n. 640, a Sc /3,) but differs in its at first lobulate, at 

 length squamulose and effigurate thallus, and scarcely less in its apo- 

 thecia and spores, which last are never many-septate. Specimens with 



