16 



from botli in the less blackened extremities. Future obser- 

 vations may induce us to unite the two species now described, 

 together with U. melaocantha, thus giving a further proof of 

 the extensive range of country occupied by the same species 

 among the lower orders of the vegetable creation. 



Fig. 1. 1. Plants {iiat. size). Fig. 2. Stem and branches; and Fig. 3. 

 Portion of a stem with a soredium : — magnified. 



