genus Hormotrichum for this latter group, adding to it, as that 
author has done, Conferva bangioides, C. Youngana, und pro- 
bably C. collabens, a species of which but little is yet known. 
In any future work I should probably bring these species toge- 
ther under one generic head, as they certainly have characters 
in common with each other, and such of them as have, like the 
present, been classed with the Lyngbye differ from the type of 
that genus in having a distinctly articulated filament. 
I have frequently observed C. flacca put forth the root-like, 
proliferous branches given in our plate. 
Fig. 1. Tufts of Lyna@pya rLacca growing on Hypnea purpurascens :—natu- 
ral size. 2. Portions of filaments from the same :—highly magnified. 
