81 
descriptions, and it is the opinion of Raciborski that the two may 
prove to be identical, yet in a note after Orthotricha Mr. Massee 
says: “I am not at all convinced in my own mind as to whether 
the present genus belongs to the present division or to the Peri- 
trichee.” ‘Which member of that very heterogeneous group could 
be imagined to have any affinity with Orthotricha is hard to guess, 
but then affinity seems not to be a necessary qualification for ad- 
mission into the Peritrichee. 
The next “Order,” Ca/otrichee is a rather compact one, but the 
limits of the included genera are utterly undefined, if we are to 
believe the author’s statements. Dermodium is reduced to Lyco- 
gaa, with the suggestion that D. conicum is nothing more than 
Lycogala epidendrum. Hemiarcyria is reduced to Arcyria! To 
reduce it to Zrichia would appear warrantable, and to reduce the 
three genera, and some others, to one, would be consistent, but 
there is little convenience and less reason in the present arrange- 
ment. To keep the number of genera the same, perhaps, we have 
a new genus, Heterotrichia, from South Carolina. All the charact- 
ers alleged are possessed in greater or less degree by species in 
other genera. Aemiarcyria is a much better genus, in that its 
characters are more important and constant. Hemiarcyria Ellis, 
Mass, separated from /. rubiformis solely on account of its warted 
spores, has been re-united with that species. 
In only four species of Zvichia is the number of spirals given. 
Counting the spirals is rather bothersome business, and the author 
is apparently not fond of mathematical exercise of this kind; still, 
he might have given the figures as others have counted them. 
Rostafinski’s distinction between Didymium and Chondrioderma 
was sufficiently flimsy, alleging that the sporangial walls in 
in Didymium always bear crystals of lime, while those of Chondrio- 
derma have a more or less compacted coating of amorphous 
Svanules. Reference to crystals is now dropped, leaving the only 
distinction in the relative compactness of the lime. Under the 
Rostafinskian method species were sometimes undecided in their 
generic preferences, but by the new arrangement it will be often 
difficult to tell where an individual should go, for example, C. or D. 
Spumarioides is frequently covered above by a smooth plate of 
lime, while on the sides and base the lime is in the form of scales, 
Or €ven a fine powder. 
