OF ARTS AND SCIENCES. 409 



diam. 2 - 2A-plo longiores. On trunks, island of Cuba, Mr. Wright. 

 Tliallus smooth, and at first pretty even, but soon becoming wrinkled, 

 and at length coarsely verrucose, pale straw-colored; the specimens 

 varying from a greenish to an obscurely brownish tint. Apothecia 

 subglobose, oftener a little depressed urceolate, with an ample rounded 

 aperture ; the largest exceeding a line in diameter. Exterior exciple 

 including, within a thalline layer (as seen by a section), the black walls 

 of the proper exciple, which disappears or loses its color below 

 (perithecium laterale, Eschw.), and is pruinose above, like the disk ; 

 the incurved margin being erose, and black-dotted by the protrusion 

 of the edge of the proper exciple. Disk flat, thin, fuscescent, clothed 

 with a bright lemon-yellow bloom ; becoming at length brick-colored. 

 Spores in eights, of middling size, colorless, from short-obtuse- 

 ellipsoid (cocciforra, Koerh.) becoming oblong-ellipsoid, 4- 6-blastish ; 

 the sporoblasts once, or even twice, more or less divided, the length 

 from twice to twice and a half exceeding the width. Paraphyses 

 filiform. The larger apothecia not unfrequently become compound, 

 processes from the walls of the proper exciple dividing it into two 

 or three small ones ; and these smaller exciples, which are exter- 

 nally more or less brownish-brick-colored, (a modification of the 

 coloring not uncommonly affecting also the summit of the common 

 margin,) are, of course, entirely free of the thallus, and distinct from it, 

 or, in other words, proper exciples, and pei-fectly visible. But in the 

 otherwise sufficiently difl^erent T. Auberianum, Montag. (which Mr. 

 Wright has abundantly collected), as explained by my valued friend, 

 the author of the species, in the place already cited, the thick veil 

 covering the disk conceals its subdivision, though this is seen in a 

 cross-section to accord with the subdivision of the veil ; the irregularly- 

 radiate processes into which the latter passes being continued down- 

 ward, more or less, through the disk. 



Thelotrema Wrightii, sp. nov. : thallo crassiusculo fragih laevigato 

 inaequabili glauco-virescente ; apotheciis majusculis mox apertis dila- 

 tatis subsessilibus scutelliformibus, excipulo exteriori margine elevato 

 pulverulento crasso obtuso carneolo demum flexuoso discum planum pal- 

 lidum albo-pruinosum cingente veloque pulverulento margini concolore 

 interrupte deraum vestiente. Sporae octonaj, incolores, lato-ellipsoidese, 

 apicibus acutis demum fusiformi-subelongata3, 4-6-blasta3, sporoblas- 

 tis intequalibus subdivisis diam. 2 - 4-plo longiores. Trunks in woods. 

 Monte Verde, island of Cuba, Mr. Wright. Thallus thickish, with at 



VOL. V. 52 



