118 LEJEUNEAE OF THE UNITED STATES AND CANADA 
Stephani, which appeared in 1892. Twenty species are recog- 
nized ; of these, Zejeunea (Eu-Lejeunea) Underwoodi and L. (Micro- 
Lejeunea) Cardoti are described as new, while L. (Euosmo-Lejeunea) 
trifaria Nees and L. (Colo-Lejeunea) Wrightii Gottsche are re- 
corded for the first time from the United States. The first of the 
new species, judging from authentic specimens, is identical with 
Lejeunea Sullivantiae Aust. and is therefore a form of Zuosmo- 
lejeunea duriuscula; the second, however, seems to be distinct. 
The specimens referred to Euosmolejeunea trifaria are dioicous 
and agree with Z. opaca, while those referred to the undescribed 
Lejeunea Wrighti, from Cuba, are apparently an abnormally devel- 
oped form of Cololejeunea minutissima. In 1895 Stephani ac- 
credited Lejeunea fava Swartz to Florida. The occurrence of this 
widely distributed species is certainly to be expected within our 
limits, but a specimen from Florida collected by Rau and deter- 
mined as L. fava by Stephani himself seems to be referable to 
Spruce's var. albida of this species, a plant which the writer is 
unable to distinguish from L. Americana. 
In the Hepaticae Americanae of Underwood and Cook, the 
first decade of which appeared in 1887, and which is still unfin- " 
ished, a number of Lejeuneae have been distributed. Those from 
the United States or Canada will be noted in connection with the 
description of species. 
It will be seen from the preceding account that the opinions of 
writers with regard to several of our species have been both varied 
and uncertain. This fact becomes even more evident when we 
consult the Lejeuneae in herbaria or in published exsiccatae. We 
are almost certain to find many false determinations among them. 
In some cases a single species will appear under several different 
names; in other cases several distinct species will appear under 
the same name. This confusion is partly because the Lejeuneae 
often grow mixed together, partly because certain of the species 
are extremely variable, and partly because the published descrip- 
tions, especially those of the older writers, are often so general and 
so incomplete as to be quite valueless. It becomes often necessary 
therefore to examine type-specimens, in order to learn upon what 
particular form a given species was originally founded. It be- 
comes equally necessary, in the case of a variable species of wide 
