412 PROCEEDINGS OF THE AMERICAN ACADEMY 



trunks, Monte Verde, island of Cuba, Mr. Wi-ight. Thallus thin, but 

 well-developed, smooth, from glaucescent-greenish becoming somewhat 

 obscurely yellowish-green, limited more or less by the blackening 

 hypothallus. Apothecia from a quarter reaching sometimes three 

 quarters of a line in diameter, innate, or at length a little prominent, 

 dilated, from roundish becoming irregular ; the cleft and recurved 

 margin, which is white-powdery within, and flecked more or less on the 

 torn edges with brown, from the protrusion of the interior layer, bor- 

 dering a thin, pale, white-pruinose disk, sometimes at length veiled 

 irregularly, in the manner of the last species and T. Auhcrianum. 

 Spores colorless, fusiform. Paraphyses filiform, conglutinate. In some 

 species which possess a distinct interior exciple (as T. lepadodcs and 

 T. albilabrum, described here) this is sometimes obscure, as if deliques- 

 cent and confluent with the powder of the disk ; and it would not be 

 difficult, on the other hand, to describe (or misdescribe) some younger 

 apothecia of the present as clothed with a delicate, or deliquescent, 

 white, interior exciple, bursting in the manner of the other species 

 cited ; though there is no trace of anything but the bloom, divided, 

 more or less, by somewhat radiant cracks, in the older ones. These 

 older apothecia are, at length, as already observed, closed more or less 

 by a thicker, subperforate vesture, due in part, it should seem, to a 

 mere thickening of the powder of the disk, but accompanied also with 

 the extension of processes from the inside of the outer exciple, or, in 

 other words, finally confluent with the latter. 



Thelotrkma mykioporum, sp. nov. : thallo tenui subcartilagineo 

 verruculoso dein aequabili kiivigato subpruinoso glaucescente ; apotiieciis 

 minutis imuiersis rotundatis apertis vel sparsis vel in series confluenti- 

 difformes aggregatis cribroso-pertusis ; excipulo exteriori urceolato 

 margine demum subprorainulo discum plano-concavum pallidum sub- 

 velatum cingente. Sporae octonjE, parvulte, incolores, ellipsoideae, regu- 

 lariter diblastn?, diam. IJ- - 2t^ longiores. On trunks of various trees, 

 Monte Verde, island of Cuba, Mr. Wright. Thallus thin, but rather 

 firm, at first finely warted, but becoming even, glaucescent, dull, or 

 even obscurely pruinose, pierced thickly with the minute rounded 

 aperture of the very numerous apothecia, which are either scattered, 

 or disposed in irregular, confluent groups ; these apertures being either 

 even with the thallus, or this last a little raised at their edges, or even 

 at length making a slightly prominent, very entire mai'gin ; the white 

 proper exciple more or less apparent within. Disk a little concave, 



