OF ARTS AND SCIENCES : APRIL 12, 1864. 269 



282) ; and Nylander (Prodr. Fl. N. Gran, in loco) refers the West 

 Indian lichen of Swartz ( JJ. cmereo-ccesia) to the European ; which, 

 especially in the var. gypsacea ("Welvvitsch Cr. Lusit. n. 97, 100, saltern 

 pr. p.), often resembles it. 



Thelotreiia latilabrum, sp. nov. : thallo crassiusculo loevigato 

 incequabili dein ruguloso e glauco olivaceo-subfuscescente ; apotheciis 

 majusculis innato-prominulis ex urceolato-scutelliformi dein dilatatis 

 ditformibus, excipulo exteriori margine lato acuto stellato-fisso retlexo 

 albo-pulverulento discum planum nigrescentem velo subcrustaceo mul- 

 tifore demum rupto coopertum cingente. Sp. in thecis cylindraceo- 

 clavatis octonfe, incolores, oblongte apice altera nunc attenuata?, 6-8- 

 blasta^, diam. 3-6° longiores. Paraphyses filiformes. On trunks in 

 the island of Cuba, Mr. Wright (Lich. Cub. n. 137). The spores 

 connect this fine Thelotrema with T. olivaceum, Mont., but externally it 

 is far more like T. Auberianum of the same author. Apothecia a line 

 in diameter, but the largest reaching two lines ; the exterior (proper) 

 exciple brown within, where it is white-powdery, and concrete with 

 the thallus without ; the interior exciple deficient. As in T. Aube- 

 rianum, the now only slightly recurved white margin of the exciple 

 remains sometimes persistently entire, being either elevated and ob- 

 tusish, or, again, scarcely exceeding the thallus ; but more frequently 

 perhaps it is deeply cleft into four or five acute, at length reflexed 

 lobes, a state characterizing the larger apothecia, while also obsei'vable 

 in others from the first. 



Thelotrema leucastrum, sp. nov. : thallo cartilagineo tenui lasvi- 

 gato pallide olivaceo-fuscescente hypothallo fusco-nigro ; apotheciis 

 majusculis innatis scutelliformibus dilatatis, excipulo exteriori reflexo 

 stellato-fisso albo-pulverulento discum planum tenuem superne nigri- 

 cantem albo-pruinosum cingente, interno deficiente. Sp. in thecis 

 subcylindraceis uniserialiter octonte, parvulte, palhde fuscescentes, e 

 cocciformi-ellipsoideo dein magis oblongte apicibus obtusis, 3 - 4-blast£e, 

 diam. 2-3° longiores. Paraphyses filiformes distinct^. Trunks in the 

 island of Cuba, Mr. Wright (Lich. Cub. n. 158). 



Var. i3 difforme : apotheciis minusculis confluentibus elongatis 

 aliterque ditformibus margine pulveraceo sub-dissoluto. With the 

 last. (Wright Lich. Cub. n. 159.) The species will be most readily 

 compared with T. platycarpum, described in a previous part of these 

 Observations, but the interior exciple, which is so distinct and elegant 



VOL» VI. 27 



