LICHENES 453 



610, TRYPETHEXIUIH, Spreng. 

 [Or. Trypa, foramen, and Thele, papilla ; descriptive of the plant.] 



Exciple double, the outer one of the substance of the thallus and 

 wart-like, including the perithecia or interior exciples. Nucleus 

 gelatinous, deliquescent. Thallus crustaceous, subcartilagineous. 



1. T. por >sum, Ach. [Porous] : Crust palish-white ; warts 

 of the apothecia somewhat prominent, broad, irregular, confluent, 

 of the same color ; within whitish. 



Hob. On smooth trunks; Beech, Ac. 



Obs. Our plant has generally passed for a form of Verrucaria 

 nitida. SCHWEINITZ called it V. composita. 



2. T. virens, Tuckerm. MS. [Green]: Crust effuse, waxy- 

 cartilagineous, smooth, green, becoming glaucescent when dry; 

 warts rather prominent, rounded-irregular, confluent, of the same 

 color with the crust ; ostioles minute, not prominent, black ; peri- 

 thecia globose (10 20), superficial; sarcothecium from fulvous at 

 length white. 



Hob. On smooth trunks ; Fagus, Acer, &c. 



Obs. The term, Sarcothecium, has been employed by FEE, to 

 denote the medullary substance of the warts, in which the peri- 

 thecia nestle. It varies in color and intensity with the species, and 

 affords an obvious character. 



We probably have other Trypethelia ; but they have not yet been 

 determined. It is chiefly a Southern genus. 



TRIBE 4. LIMBORIAH3EAE. 



Apothecia rounded, the carbonaceous proper exciple closed, at length variouely 

 dehiscent ; nucleus subccraccous, rigescent ; thallus crustaceous. 



611. GYROS'TOMUItt, Fr. [Conotrema. Tuckerm. Syn.] 



[Gr. Gyros, a circle, and sioma, mouth ; descriptive of the plant.] 

 Perithecia mostly solitary, horny, black, at first pertuse, becoming 

 open, with a coarctate inflexed margin, including a depressed nucleus 

 which is elevated at the centre into a somewhat marginate disk. 

 Thallus crustaceous. 



1. G. lirceoldtum, Fr. [Urceolate]: Crust thin, smooth, 



rugose-rimose, glaucous-white, bordered by a black line ; perithecia 



scattered, at first covered, finally superficial, conoidal, white-prui- 



nose. 



I lab. On trunks, and branches : common. 



SUBORDER III. COLLEMA V CEAE. 



Filamentous or foliaceous gelatinous-conglutinate plants, without discrete layers; 

 sporidia included in asci, and immersed in a thalamium, which Is contained either 

 in a thalhne exciple, or a proper exciple. 



TRIBE 1. COLLEMFAE. 



Thallus gelatinous-conglutinate, caulescent or foliaceous. 



