32 



1 12. Aioina. Peristome contorted. Leaves strongly 

 involute above; filaments very numerous; costa very broad. 

 Stem very short. Pedicel of the capsule long. 



113. Crossidium. Peristome usually contorted. 

 Leaves reflexed or flat at the borders, imbricate ; filaments 

 numerous; costa narrow. 



114. Pterygoneuron. Peristome not contorted, mostly 

 wanting. Leaves imbricate, not involute; lamellae few; 

 costa narrow. Monoecious. 



II. Didymodontece. Peristomial teeth not partite 

 but more or less cleft (or in Pottia entire), with longi- 

 tudinal line, not contorted but sometimes half-twisted; 

 basal tube very short. Leaves without lamellae on the 

 costa. 



* Capsule symmetric without distinct neck. 



115. Didymodon. Peristomial teeth more or less 

 cleft. Leaves usually papillose, generally broader near 

 the base. Habit of Barbula (Eu-Barbula). 



116. Pottia. Peristomial teeth not cleft, often rudi- 

 mentary or wanting. Leaves broader above the middle, 

 often smooth. Habit of Barbula (Tortula). 



** Capsule oblique or arcuate with a thick neck. 



117. Dermatodon. Peristomial teeth cleft. Leaves 

 papillose, broader above the middle. Habit of Ceratodon. 



III. Weisiece. Peristomial teeth without longitu- 

 dinal line, not twisted, generally short and entire (rarely 

 cleft), sometimes wanting; basal tube not distinct. Leaves 

 without lamellae. 



118. Weisia. Capsule without neck, generally 

 straight and symmetric. Leaves usually papillose, not 

 limbate, not seldom involute above, often crisped when dry. 



IV. Syrrhopodontece. Peristomial teeth without 

 longitudinal line and basal tube, not twisted, short and 

 entire. Leaves bilamellate at the borders or limbate, 

 often with propagula. 



119. Syrrhopodon. Capsule straight and symme- 

 tric, subcylindric, nEurowed above to the mouth, long- 



