410 PROCEEDINGS OF THE AMERICAN ACADEMY 



length a diameter of a quarter of a line, very brittle, glaucous-greenish. 

 Apothecia soon open, suburceolate, becoming scutelliforra, and sessile, 

 or at length often a little elevated, and larger than in any other known 

 species (exceeding two lines in diameter) ; the exterior exciple border- 

 ing with a somewhat elevated, thick, obtuse, powdery, pale-flesh-col- 

 ored, finally flexuous margin the thin, colorless, wliite-pruinose disk 

 (seen, by a section, to be included within a fuscescent layer, passing 

 upwards into, and conditioning, the margin), which it also, at length, 

 interruptedly covers with thick processes of the same color and sub- 

 stance as the margin ; tliis development (veil) being, however, less con- 

 tinuous than in other species, and often deficient. Spores colorless, 

 ventricose-ellipsoid with acute tips, or at length longer and rather 

 broad spindle-shaped, 4- 6-blastish ; the sporoblasts unequal in size, and 

 one or more of them finally divided, from twice to four times longer 

 than wide. Paraphyses filiform, ratlier distinct. What is above 

 described as the veil appears to be analogous to what Montague (sub 

 T. Auberiano, Cuba, 1. c.) has called by the same name ; this being un- 

 derstood by him as indicating an extraordinary condition of the interior 

 exciple. But in the species before us this veil appears rather to be a 

 result of a nisus of the proper exciple (which I understand as concrete 

 with, or making the inner wall of, the exterior exciple) to become com- 

 pound, exactly as in T. auratum ; the processes which make it up being 

 evidently similar in aU respects to the inner wall, and their color con- 

 ditioned, in both the species mentioned, by the color of that. It cannot, 

 therefore, if these observations are correct, correspond with the interior 

 exciple of T. lepadinum, which must be regarded as deficient in these 

 species, or only represented by the bloom of the disk. 



Thelotrema globulare, sp. nov. : thallo cartilagineo-membra- 

 naceo liEvigato e glaucescente pallide fuscescente, hypothallo nigro- 

 limitato ; apotheciis submediocribus superficialibus depresso-globosis 

 urceolatis excipulo exteriori margine obtuso aperturam impressam 

 poriformem cingente, disco plano-concavo pallido subvelato. Sporaj 

 octonae in thecis lineari-clavatis, incolores, obtuse ellipsoidese vel 

 oblonga3, tetrablasta^ ; sporoblastis regularibus diam. 14^-21-plo longi- 

 ores. Trunks, in the island of Cuba, Mr. Wright. Thallus tliin, but 

 well-developed, smooth, from glaucescent becoming very pale brownish, 

 bordered, often conspicuously, by the black edge of the hypotliallus. 

 Apothecia of the color of the thallus, becoming whiter above, a 

 few of the larger ones half a line in diameter, depressed-globular, the 



