(253) 
with this the widely different C. Schwednitzd7, distributed by the 
collector after whom it is called. Braun was from an early date in 
correspondence with American collectors, especially Engelmann, 
and almost all publications here have been profoundly influenced 
by him. Dr. T. F. Allen of New York has been by far the most 
assiduous collector and student of the family on this side of the At- 
lantic; he accumulated a very large herbarium, which has made the 
present paper possible. He projected an extensive work, to include 
all American representatives of the group, but was unable to com- 
plete it. Many species were collected by Charles Wright, botanist 
of the Mexican Boundary survey, in 1851-2. These passed through 
the hands of Engelmann, Braun, and Allen, and have often been 
cited. 
The only paper yet published, intended to comprise all North 
American representatives of the family, was by Halsted, in 1879. 
The collections upon which it was based were mainly from New 
England and the total was only 24: JV2tella 8 species, Tolypella 1 
species, and Chara g species and 6 varieties. In Fragmente einer 
Monographie der Characeen, compiled from Braun’s notes by 
Nordstedt after the death of the former, and published in 1882, there 
are North American identifications under 39 specific headings, 21 
in Witella, 3 in Tolypella, and 15 in Chara, besides which many 
varieties and forms are recorded. 
n important paper covering a limited range is that of Woods in 
the Flora of Nebraska, in which 5 species of JVétedla and 7 of Chara 
are described and figured. 
SYNOPSIS OF THE GHNERA OF CHARACEAE 
Crown-cells in two superimposed rows, each of § cells ; cortex and stipulodes 
wanting. Su bfamily NITELLEAE. 
Antheridia terminal on the primary ray and secondary divisions of the 
leaf. 
Antheridia lateral on the nodes of the leaf, or within the ae of the 
bh 2. Tolypella 
whorl. - Lypella. 
Crown-cells in a single row. Subfamily CHAREAE. 
Stipulodes none. 3. Nitellopsis. 
Stipulodes present, sometimes reduced. 
Sporocarps below the antheridia. 4. Lamprothamnus, 
Sporocarps ahaty the ecanciien 5. Lychnothamnus, 
Sporocarps above idia or in dioeci P on the upper 
side of the nodal cell of a leaflet. 6. Chara 
