284 Piof. Dr. C. IMeresclikovskj's Diagnoses 



paper, "Mat^riaux pour une Monographie du Genre Graphis^^^ 

 in ' Annuaire du Conservatoire et Jardin bolanique de 

 Geneve/ vol. xxi. 1921. Anotlier set of new species, 

 varieties, and forms of different kinds of lichens, also accom- 

 panied witli Latin diagnoses, can be found in my paper 

 " Schedulae ad Lichenes ticinenses exsiccatos " in the same 

 'Annuaire du Conservatoire botan. &c./ vol. xxi. 1919, 

 pp. 145-216. 



In my previous paper in this Magazine, " On some new- 

 Forms of Lichens" (Ann. & Mag. Nat. Hist. ser. 8, vol. vi. 

 p. 482, Nov. 1920), the two following should be added to 

 the list of forms belonging to Physcia pulverulenta (pp. 484- 

 485) : — forma nigricans, Miili. Arg. (Classif. p. 35 ; Fhigey, 

 Licb. d. 1. B^anche-Comt^, i. p. 182), and (ormsinuda, Harm. 

 (Lich. d. Fr. p. 634). 



Correction. 



While my paper " On some new Forms of Lichens,'^ 

 recently published in this Magazine (vol. vi. 1920, p. 482), 

 was in the press, I sent to the editors two supplementary 

 forms to be added to those belonging to the species Fhyscia 

 pulverulenta {/. c, p. 484), of which one — forma nigricans, 

 Mull. Arg. — has been erroneously put as a form of the var. 

 angustata, to which it does not belong, being a form of the 

 species itself, while the other — forma nuda, Herm. — has 

 been omitted altogetlier. 



After correcting these errors and adding another form 

 which I previously omitted (forma deminuta, Cromb.), the 

 list of forms belonging to Physcia pulverulenta will now read 

 as follows : — 



1. Phi/scia puhsiulenta (Schreb.), Nyl. 



2. , forma deUcata, Mer. 



3. , forma deminuta, Crotnb. Brit. Ijich. i. p. 306. 



4. , forma qramdosa, Mer. (Hedw. 11)19, p. 227). 



Tu , subforma/?7/hcM/o5fl, Mer. (Hedw. 1919, p. 228). 



6. , forma nifjricans, Miill. Arg. (Classif. p. 35). 



7. , forma nuda, Harm. Lich. d. Fr. p. 634. 



8. , iovn\?i 2)olita, Flot. ♦ 



9. ■ , forma rugosa, Mer. (Hedw. 1919, p. 229). 



10. , forma subvcnusta (Nyl.). 



11. , forma tunjida (Schaer.), |larm. 



12. , forma turyidiUa, Mer. 



13. , forma venustoides, Mer. (Hedw. 1919, p. 229). 



14. , var. anr/ustata (Hoffm.), Ach. 



15. , forma convexa, Mer. 



16. , forma elegantella, Mer. 



17. , forma nuda, Mer. (Hedw. 1919, p. 230;. 



18. , var. aquiloides, Mer. 



