﻿Evans: The genus Plagiochasma 281 



Raddi (type of Rehoulia maderensis), G. Don; near Funchal, 

 1858, Johnson; Como do Lobos, August, 1896, W. Trelease. 



Canary Islands: Palma, 18 15, C. Schmidt; February, 1888, 

 O. Kuntze; Bocco de Bufadero, Teneriffe, January, 1906, C. J. 

 Pitard (distributed in Plantae canarienses, No. 762). 



Cape Verde Islands: Green Mountains, St. Vincent, date 

 and collector unknown. 



Ascension Island: without definite locality or date, J. D. 

 Hooker 22 (type of Jungermannia [Fegatella] limbata). 



St. Helena: without definite locality or date, Lieut. Houghton 

 33- 



Abyssinla.: locality, date, and collector unknown. 



Transvaal: Muller's Farm, MacLea (distributed in Reh- 

 mann's Hepaticae austro-africanae. No. 32, as ''Plagiochasma 

 muricatum Steph.," but probably representing a part of the type 

 material of P. tenue). 



Australia: Swan River, West Australia, 1846, T. Drummond. 



New Zealand: without definite locality or date, /. D. Hooker 

 (type of Jungermannia [Fegatella] australis). 



Aside from several other " localities in Italy and the At- 

 lantic Islands, P. rupestre has been recorded from Greece, from 

 Dalmatia, from southern France and Corsica, from Portugal, 

 from Cape Colony, and from Asia Minor. Whether the plant 

 from Schen-si, China, collected by Father Giraldi in 1896 and 

 described by Massalongo (21, p. 49) under the name P. elongatum 

 /3 ambiguum, belongs here or not cannot be decided from lack of 

 specimens. According to the description, which tells nothing 

 about the epidermal pores, the spores are subrugose (or rugulose) 

 and not reticulated. Such a peculiarity would exclude the plant 

 not only from P. rupestre but probably from the genus Plagio- 

 chasma altogether. The author intimates, however, that the 

 spores may not have been mature, so that no definite conclusions 

 can be drawn from them. 



i\lthough P. rupestre has not been considered an especially 

 variable member of the Marchantiaceae, it nevertheless exhibits 

 considerable diversity in size, in color, in the distribution of its 

 male and female inflorescences, and in the structure of certain of 

 its organs and tissues. Some of this diversity at least is due to 



