5& HANDBOOK OF BRITISH HEPATIC/E. 



compressed, mouth truncate, obsoletely four-lobed. 

 Andraecium terminal on the branches, bracts two 

 or three joined, except for the lobule somewhat 

 larger, scarcely differing from the leaves. 



Sub-tribe II PORELLEM. 



Branches all lateral, intra-axillary ; leaves 

 incubous, lobules of equal size. Perianth 

 with the mouth lacinulate, at first constricted, 

 at length gaping and bilabiate. Capsule four- 

 valved, the valves often incompletely discon- 

 nected at the base, irregularly split. 



Genus 5. PORELLA, Dill. 



Branches lateral, intra-axillary, pinnate; 

 leaves incubous, deeply lobate. Perianth at 

 first constricted, then gaping and two-lipped. 

 Capsule globose, rarely valvate to the very 

 base. Dill. Hist. Muse. ( 1 74 1 ). Madotheca, 

 Dum. Comm. (1823). Vide Spruce Hep. 

 Amaz. p. 326. 



Porclla differs from all Radiihe in the regularly 

 pinnate and feather - like stems ; the axillary 

 branches (not infra-axillary, as in Radula, but intra- 

 axillary) ; the universal presence of underleaves, 

 the basal angles of which, like the external base of 



