Mr. Brown on Lyellia, Leptostomum, and Buabaumia. 579 
By these lines also S. squarrosum is readily distinguished from 
Octoblepharum, in which the apparent number of teeth is the 
same: for in Octoblepharum each tooth has only a single pellucid 
line; and hence its affinity to certain species at present referable 
to Weissia, with a nearly similar habit and sixteen distinct teeth, 
whose axis is not perceptibly pellucid. 
Weissia splachnoides differs from the other Splachnee in having 
sixteen equidistant teeth; but as these teeth, according to the 
indication of the pellucid axis, are double, the arrangement may 
be compared with that of Tayloria and Systylium, in which the 
separation into thirty-two is complete, and the sixteen pairs equi- 
distant. It agrees, however, also in this respect with Grimmia and 
with several species of Weissia : but in other important characters, 
as well as in habit, it is evidently related to Splachnum, and offers 
perhaps one of the best examples of the importance of the male 
flowers in distinguishing natural genera. 
Even Tetraphis pellucida may be cited in proof of the same pre- 
vailing number in the peristomium ; each of its four teeth, when 
highly magnified, appearing to have seven longitudinal striæ, 
which, according to this test, would make the real number thirty- 
two; a structure contributing to fix the place of Tetraphis in the - 
natural series between Splachnum and Orthotrichum. — 
observed it of the same foai in specimens from Madagascar. There seems, therefore, no 
reason to doubt that these two mosses differ materially even in this part of their structure $ 
and as other differences, of at least equal importance, also exist, both in the peristomium 
and male flowers, Octoblepharum serratum, whose habit is nearly that of Splachnum, may 
be distinguished both from that genus and from Octoblepharum by the following characters, 
OnTHODON. 
Fl. Fem. terminalis. : 
Peristomium simplex, octodentatum, dente singulo striis tribus lengitudinalibus instruct 
(ideoque e quatuor coalitis composito). 
Calyptra mitriformis (4-fida, pilosa). 
Fl. Mas terminalis, discoideus. 
VOL. XII. ÅT Better 
