578 Mr. Brown on Lyelka, Leptostomum, and Buxbaumia. 
The number of teeth in SPLACHNEZ is thirty-two, which, how- 
ever, are never entirely distinct and at the same time equidistant, 
but approximated or united in various degrees in the different 
genera and species of the section. 
Thus in Tayloria and Systylium the thirty-two teeth are distinct 
and disposed in sixteen pairs. 3 
In Splachnum rubrum and luteum there are apparently only eight 
pairs, each tooth, however, having a pellucid and obscurely-perfo- 
rated axis. In almost all the other genuine species,of Splachnum 
there is the same disposition as in S. rubrum and luteum ; but the 
pellucid axis of each tooth is less distinct and imperforated. 
In Splachnum angustatum, and I believe also in a second spe- 
cies nearly related to it, the arrangement is somewhat different; 
for the sixteen apparent teeth are approximated, and at the base 
even united in fours, the pellucid axis of each tooth being still less 
obvious. Hence these species in their peristomium very nearly 
approach to Tetraphis, to which they would be absolutely referable 
were the union complete. 
In Splachnum squarrosum the apparent number of teeth is eight, 
without any actual subdivision. But as each tooth has three 
equidistant pellucid lines, of which the lateral are nearly as di- 
stinct as the central, there can be no doubt that the composition 
is the same here as in the rest of the section*. 
| n By 
* In a late number of Musci Exotici, (No. 17. tab. 136.) Splachnum squarrosum is 
transferred to Octollepharum, and, on the authority of M. de Beauvois, is stated to be 
Octoblepharum serratum of Bridel. Mr. Hooker, however, continues to refer it to this 
genus, on the supposition of its agreeing with the original species in the form of its ca- 
lyptra : observing that if this should prove not to he the case, it ought to be separated, 
under the generic name Orthodon, formerly given to it by its discoverer M. Bory de 
St. Vincent. 
The calyptra of O. albidum is represented as distinctly cucullate, both by Swartz (in 
Ols. Bot. tab. xi, fig. 1.) and M. de Beauvois (in Flore d' Oware, i. tab. 31.). I have also 
observed 
