62 



Leaves consisting of large, loose cells, not hairy. Peristome teeth 



irregular, lanceolate, two cleft, often cut short. POTTIAC K i;. 

 Leaves consisting of small, dense cells. 



Peristome teeth perforated with numerous holes, or irregularly two 

 or three cleft. Leaves often hairy. GRIMMIACK i:. 



Peristome teeth ragged, often abortive. Leaves channeled, not 

 hairy. Capsule with a large mouth. SELIGERIA< i: i.. 



Peristome teeth irregular. Leaves lance linear. Capsule with a 

 mouth of moderate size. WKISSIACE^E. 



139. Leaves blue-green when moist, white when dry, very spongy. 



LEUCOBRYACE.K. 

 Leaves grass-green or yellow. 



Teeth of the peristome undivided at the apex, but with a wide crack 

 or cleft in the middle of the base and extending half way up. 

 Calyptra open on one side almost the whole length, somewhat 

 twisted. Leaves without ribs. Plants small and almost ,-tnu- 

 less. DISCELIACE K. 



Teeth of the peristome purple. 



Teeth long, divided to the base into two round, thread-like limbs, 

 remotely jointed. CERATODONTACE^E. 



Teeth closely jointed, usually divided half way down but some- 

 times to the base into two unequal limbs, the narrower limbs 

 of adjacent teeth standing next to each other. Leaves ribbed. 



WEISSIACE.K. 



140. Teeth thirty-two, thread-like, arranged in pairs. GRIMMIACE.K. 



Teeth thirty-two or sixty-four, lanceolate, joined to the columella. 



Calyptra with a roughened surface, or slightly feathery at the 



apex. POLYTRICHACE^t. 



141. Inner peristome formed of a keeled membrane, with or without 



fine hairs. 142 



Teeth of peristome without a common membrane at base, Inner 

 peristome composed of fine hairs. 



