40 ACOTYLEiioNs.-— LICHENS. Variolcma. 



greyish, waits of the apothccia convex half iinmersed whiter, 

 orifices mucli contracted radiated with fissures concealing the 

 fiesii-coloured apothceia. Ach. Sfj/i. Lick. p. 116. Lichen 

 exanlfiemalicus, p. 1184. 



Hab. C/alcarcous rocks, Dickson. 



Of this veiy pretty little Lichen, Acharius observes, that it has a habit 

 peculiar to itself; but that it corresponds better with this genus 

 than with any other. 



13. PYRENULA. 



Universal receptacle crustaceous, spreading, plane, adnate, uni- 

 form ; with wart-like processes including or surrounding at the 

 base a solitary, simjjle, thick (black), papillary partial re- 

 ceptacle, which contains a globose cellular Jincleus. 



1. P. riigrescej's, crust tartarcous somewhat tessellated unequal 

 brownish black, warts of the apothecia spreading at the base 

 depressed somewhat rugose surrounding the greater ])art of the 

 ])rominent apothecia. Ach. Syn. Lick. p. \'2G. Ferrucaria 

 ■imbriiia, E. B. t. 1499. 



Hab. Hocks, not uncommon, Mr. Turner and Hook. 



14. VARIOLARIA. 



Universal receptacle crustaceous, expanded, plane, adnate, uni- 

 form. Partial receptacle warted, formed of the tliaUus (ge- 

 nerally sorcdiform), somewhat margined (white). Nucleus 

 compressed, cellular, concealed within the substance of the warts. 



1. V. aniara, crust rugose cracked uneven subpulverulent white 

 or greyish, warts of the apothecia appressed plano-concave 

 margined bearing soredia of the same colour as the crust. 

 ylck. Syn. Licit, p. 131. Lichen J'agineus, Lightf. p. 807. 

 £.5.^.1713. 



/3. discoidea, crust pulverulent white at length greyish naked, 

 sovedia crowded at length spreading waved plano-concave with 

 the margin raised swollen. Lichen discoideiis, E. B. t. 1714. 

 _L. carpineits, Lightf. p. SOJ. 



Hab. a. On the bark of beech, oak, and other trees, frequent. /3. On 

 the smooth bark of beech and other trees, Lightf., Hopk. 



Var. a. is highly bitter. Mr. Turner observes, that the bitter flavour 

 is not found in 3. 



2. V. lactea, crust tartareouj distinctly bordered cracked smooth 

 white the circumference somewhat zoned crenato-lobate, warts 

 of the apothecia crowded margined very white and pulverulent. 

 Ach. Syn. Lick. p. 132. E. B. t. 24lO. 



Hab. On rocks, common. Vvliin stones^ on Campsie and Cathkin 

 .hills, Hopk. 



