578 il/r. BuowN on T.yeUia, Leptostoinum, and Buxbauniia. 



The number of teeth in Splaciine;e 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 tlie section. 



Thus in Tai/loria and Sijsfi/Uian the thirty-two teeth are distinct 

 and disposed in sixteen pairs. 



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 Splachrium 

 there is the same disposition as in S. rubrum and luteum; but the 

 pellucid axis of each tooth is less distinct and imperforated. 



Jn 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*. 



By 



* In a late number of Musci Exolici, (No. 17. tab. 136.) S/ilachnum squarrosum w 

 transferred to Octollepliarum, and, on the authority of M. de Beauvois, is stated to be 

 Octoltepharum serralum 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 be the case, it ought to be separated, 

 under the generic name Orlhodon, formerly given to it by its discoverer M. Bory de 

 St. Vincent. 



The calyptra of O. albidum is represented as distinctly cucuUate, both by Swartz (in 

 Obs. Bot. tab. xi. fig. I.) and M. de Beauvois (in Flore d'Oware, i. tab. 31.). I have also 



observed 



