168 LICHENES. [Variolaria. 



d. Apothecia opening into depressed or hollow shields or pustules 



(variola). 



Fam. VI. Variolarie,e. 



11. Variolaria. Pers. Variolaria. 



Thallus crustaceous, membranaceous, adnate, spreading, uni- 

 form. Apothecium a suborbicular, scutelliform cup, formed of 

 the thallus, filled with a powdery or flocculose substance, which 

 covers an immersed waxy disk containing imbedded tfiecce. — 

 Name ; variolce ; from the apothecia resembling the pustules of 

 the measles or small-pox. — " The Genus appears a natural one, 

 but bordering upon many others. By S. Vitiligo it is connected 

 with Spiloma; by V. multipunctata with Thelotrema, (or rather 

 perhaps Pevtusaria); by V. arge.na (still more by V. velata) 

 with Parmelia, (Lecanora, Ach. Syn.) ; and by V. agelcea with 

 Urceolaria ; while by Isidium paradoxum there is a close 

 affinity with that genus." Turn, and Borr.; whose arrange- 

 ment and character are here followed. — In V. velata the place 

 of the powder or soredia in the apothecia is occupied by a thin 

 membranous veil drawn over the disk. 



1. V. Vitiligo, Turn, and Borr. {leprous Variolaria); crust 

 elliptical almost filmy very thin smooth whitish indeterminate, 

 apothecia very numerous minute oblong confluent with a very 

 narrow elevated margin, powder lead-coloured. Turn, and 

 Borr. Lich. Br. p. 53. — Spiloma Vitiligo, Ach. Meth. p. 10. 

 t. l.f. 4. E. Bot. t. 2073. Lecanora apochrcea, Ach. Syn. p. 162. 



Common on old rails and gate-posts. 



2. V. griseo-virens, Turn, and Borr. {greyish-green Vario- 

 laria); crust elliptical inclining to tartareous thin slightly 

 rugged grey nearly indeterminate, apothecia small nearly 

 orbicular with a very narrow elevated border, powder greenish- 

 grey. Turn, and Borr. Lich. Br. p. 54. E. Bot. t. 2400. 



Birch-trees on Stratton-Stravvless Heath, Norfolk, Mr. D. Turner. 

 On Cherry bark at Killarney, Sir T. Gage. 



3. V. conspurcdta, Turn, and Borr. (dusty Variolaria); 

 thallus suborbicular tartareous thick whitish surrounded when 

 young by a zonate border of various colours, apothecia minute 

 inconspicuous with a depressed evanescent border, powder grey. 

 Turn, and Borr. Lich. Br. p. 57 .—Lichen conspurcatus, E. 

 Bot. t. 964. (with black parasitical bodies represented in the 

 magnified figure.) — Lecidea ? conspurcata, Ach. Meth. p. 50. — 

 L. margaritacea, /3. Ach. Lich. Un. p. 187. — (3. lateritia ; crust 

 very thin copiously sprinkled with lead-coloured apothecia. 

 Turn, and Borr. I. c. — y. albella ; crust continuous but slightly 

 rugose, both it and the apothecia white. Turn, and Borr. I. c. 



