c 



ON LICHENS or THE 'CHALLENGEtt' EXPEDITION. 211 



2. They are transformed into petals, 



3. -4rr<?5^ of lateral parenclijma between the branches of the 

 veins causes several of the petaloid stamens to become lacinfated. 



4. Change of sex has occurred, by which the petaloid filament 

 developed style and stigma ; and the margins and even the mid- 

 ribs had become placentiferous and produced rudimentary ovules. 



Pistil, — This organ remained normal in all the flowers exa- 

 mined. 



Contributions to the Botany of H.M.S. ' Challenger.' 



XXXIX, The Lichens of the * Challenger ' Expedition (with a 

 revision of those enumerated by Dr. J. Stirtonin Linn. Journ. 

 Bot. xiv. pp. 366-375). By the Eev. J. M. Ckombie, F.L.S. 



&c. 



[Bead June 7, 1877.] 



Cape Verde. 



1. SCTTONEMA sp. ? [ 



J 



On rocks, Bird Island : very sparingly and sterile. (This is 

 probably a new species, buf is not sufficiently developed to be fully 



d) 



) 



On rocks : sparingly gathered. (There are no apothecia visible 

 on the two fragments returned, so that the species is uncertain. ) 



3. EOCCELLA TINCTORIA, DO. 



On rocks : fertile. [N.B. There are also smaller and more 

 slender states from Bird Is4land,=i2. j^atellata, Strn., sp. n.] 



4. Eamalika eigida (Pers.) l=B. scopulorum^ van tenuior^ 



Strn.]. 



On the ground : sterile. 



5. E. CUSPIDATA, var. cbassa, Del. [ = JR. polpnorpha]. 

 On maritime rocks : fertile and somewhat variable. 



6. R. iifTEKMEDiA, Del.[^=B.farinacea]. 

 On the ground : sterile. 



On rocks : barren. 



r = P. tiliacea^ var, $cortea] . 



In this and the following instances I give Dr. Stirton's determinations 



1^ ^ 



brackets 



