58 HANDBOOK OF BRITISH HEPATIC^. 



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. PORELLE&. 



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. (1741). Madotheca, 

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

 Amaz. p. 326. 



Porella differs from all Radulce 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 



