20 



simple. Stem bi-tripinnate ; the naked part long; para- 

 phyllia numerous. 



IV. Thamniece. Upper leaf-cells generally round- 

 rhombic, the middle suboval. 



40. Thamnium. Endostome with appendiculate cilia. 

 Pedicel of the capsule smooth. Alar leaf-cells few, small 

 and not much distinct ; costa simple. Stem with fasciculate 

 branches or pinnate; the naked part mostly long; para- 

 phyllia none. 



Fam. 12. Thuidiacese (new fam.) 



A. Costa of the leaves short, mostly double, or 

 indistinct. 



a. Leaves erect or appressed when moist, not 

 recurved; costa double or indistinct. Capsule suberect. 

 Branches erect; paraphyllia wanting. 



41. Myurelia. Leaves cochleariform ; cells rotun- 

 date. Branches julaceous. 



b. Leaves patent or spreading when moist, some- 

 times recurved; costa sometimes simple. Capsule usually 

 inclined. Branches decumbent; paraphyllia few or wanting. 



42. Heterocladium. Leaves spreading and claviculi- 

 form or subfalcate when moist, generally dimorphous; 

 those of the stem seldom appressed when dry; middle cells 

 oval-oblong. 



43. Pseudoleskeella (new genus.) Leaves not sprea- 

 ding when moist, appressed when dry, not seldom homo- 

 morphous; cells generally round-oval. 



B. Costa of the leaves long and simple, mostly 

 subpercurrent. 



44. Pseudoleskea. Leaves homomorphous. Stem 

 not regularly pinnate. 



Leaves sometimes not papillose, not seldom falcate, 

 mostly patent when dry; cells oval-oblong or narrower. 

 Stem usually with paraphyllia. 



45. Thuidium. Leaves dimorphous. Stem pinnate. 

 Leaves usually papillose, not falcate, appressed or 



