RET. J. M. CROMBIE ON MADAGASCAR LICIIENS. 409 



DESCRIPTION OF PLATE VI, 



Fig. 1. A small branch of Acacia spkcgrocephala, natural size: k, k, h, the 



hollow thorns ; g, g, the nectar-secreting glands. 



2. Part of a leaflet of Acacia ( X 5*7) : /\ / 2 , / 3 , the three lower food- 

 bodies on one side; p the dwarfed point of the upper leaflet correspond- 

 ing to/ 3 . 



3. Transverse section of food-body of Acacia, treated with solution of potash 

 to show the oil globules. (Hartnack No. 8.) 



4. The^same, treated also with creasote and turpentine (Hartnack No. 8) to 

 remove the oil and show the protoplasmic matrix. 



5. Cecrapia peltata. Development of a food-body. (Hartnack camera 

 lueida with objective No. 5.) 



6. Young plant of common Brake Fern, Pteris Aquilina, showing the nectar- 

 glands, g 1 , g 2 . 



i 



Lichens collected by W. Pool, Eeq., in Madagascar. 



By the Rev. J. M. Crombie, F.L.S. 



[Read June 1, 1876.] 



Judging from its climate and situation, there can be no doubt 

 that the island of Madagascar possesses a very rich and extensive 

 lichen-flora. Unfortunately, however, it is still in this respect 

 almost entirely a terra incognita ; nor does the present small col- 

 lection throw much light upon its lichen treasures, though it 

 affords some indications that these are both valuable and varied. 

 No habitats are attached to the specimens, all of which were 

 gathered near A_ntananarin, the capital of the island ; but it may 

 be presumed that they are entirely corticole. 



Sph^erophoron madagascareum, Nyl. 9 sp. n. 



"Thallus albidus, erectus, compressiusculus (latit. fere 1 millim. vel an- 

 gustior, crassit. 0*2 millim. vel etiam tenuior), dichotome divisus, 

 evernioideus (altit. circiter 3 centimetrorum vel minor); apothecia 

 primum in globulo thallino albo inclusa, deinde globulum nigrum nu- 

 dum fingentia (latit. 0'5-0'7 millim.) ; sporae 8nse, globosae, diam. 

 0*004-0005 millim. Species omnino distincta, nulli alii affinis." 

 Nyl. in lift. 



The thallus is somewhat glaucescent above, and beneath more 

 purely white. Occasionally, as in the other species of the genus, 

 it is more or less tinged of a reddish or pink colour. From all of 

 these, however, it differs very remarkably in the situation of the 

 apothecia, which are not terminal on the apices of the primary 

 axes, but scattered chiefly towards the extremities of the branches. 



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