70 



margins of the wings and with a costa of the type found in 

 M. grandiflora. These species are M. comata Steph. (of New 

 Caledonia), M. glaherrima Steph. (of Chile, Patagonia, New 

 Zealand and Australia), and M. siniiata Loitles. (of Peru). The 

 first and third of these are known to the writer from description 

 only. In M. comata the plants are epiphyllous, the thallus is 

 plane, and the cells of the wings are unusually large, measuring 

 126 X 54 M according to the description. In M. glaherrima the 

 thallus is plane and is often naked throughout, even marginal 

 hairs being absent; the female branch, moreover, bears surface 

 hairs, as is usual in the genus. In M. siniiata, which is known 

 only from the original material, the thallus is strongly convex 

 as in M. grandiflora, but the wings are often thirty-five cells 

 wide, the hairs are 150 /i long, and the margin is described as 

 being deeply sinuate or, rather, interruptedly recurved, a con- 

 dition which is apparently never duplicated by M. grandiflora. 

 Unfortunately M. sinuata was described from sterile material, 

 and there may be difficulty in recognizing it again. 



Sheffield Scientific School, 

 Yale University 



