Jennings — Tivo Neiv Species of Phycopeltis, New Zealand. 763 



It seems that the conditions, whatever they may be, which favour 

 the growth of Phycopeltis and Cephaleuros are also suitable for 

 several forms of fungi. This is only what might have been expected, 

 but it is remarkable that these associated forms should be so similar 

 in India and Ceylon, on the one hand, and New Zealand on the 

 other. 



When the alga is attacked by a true lichen-forming fungus the 

 effect is very different. In the present instance the result is not 

 only the formation of a well-developed and fertile Strigula, but of one 

 S. complanata. Fee, specifically identical with that which in Ceylon 

 develops in connection with Cephaleuros mycoidea} 



On many of the leaves of JSTesodaphne covered with Phycopeltis 

 expansa, the opaque white thallus of Strigula with its black perithecia 

 appears in patches, usually at the margin. 



Examined with a lens, a narrow green band may usually be ob- 

 served bordering the thallus and separating it from the yellow alga. 

 Under the microscope this green zone is seen to consist of a spreading 

 network of hyphse penetrating the algal disc, causing its cell-contents 

 to separate, become green and rounded, and with or without division 

 pass into the condition of gonidia. 



The process is similar to that observed by Cunningham and Mobius. 

 In the case described by Marshall "Ward the algal disc appears to 

 remain fairly continuous within the lichen thallus. In the younger 

 parts, it is true, the gonidial layer may be thin and appear in section 

 as a row of somewhat quadrate cells, but I believe in the fully 

 developed lichen there is always division and rounding off of the cells 

 as they become green. 



With respect to the relations of Phycopeltis nigra with fungus 

 hyphse, the results of my examination are entirely negative. When 

 associated with Phycopeltis expansa and when the latter is full of 

 the brown intercellular hyphse mentioned above, the dark-coloured 

 species is never affected by these filaments or by any other fungoid 

 elements. 



^The genus is common through the Tropics, but I believe has not been 

 recorded from New Zealand. It is not included in Nylander's Sjmopsis of New 

 Zealand lichens, published in 1888. Some so-called species have been founded on 

 different stages of development in connection with Cephaleuros. The British 

 Strigula BaUngtoni is stated by M. Hariot to contain no gonidia, and the speci- 

 mens I have seen certainly appear to be fungi, not lichens. 



